1) The boron atom has only one unpaired electron, making it paramagnetic.
2) Boron atom has one unpaired electron, making it paramagnetic.Iron atom has four unpaired electrons, making it paramagnetic.
1. Boron atom and unpaired electrons Boron is a chemical element with the symbol B and atomic number 5. It is a trivalent metalloid and has three valence electrons. The electron configuration of boron is 1s² 2s² 2p¹. Therefore, the boron atom has only one unpaired electron, making it paramagnetic.2. Iron atom and unpaired electronsIron is a chemical element with the symbol Fe and atomic number 26. It is a metal and has two valence electrons. The electron configuration of iron is [Ar] 3d⁶ 4s². Therefore, the iron atom has four unpaired electrons, making it paramagnetic. Answer:Boron atom has one unpaired electron, making it paramagnetic.Iron atom has four unpaired electrons, making it paramagnetic.
Learn more about electron here,
https://brainly.com/question/12994141
#SPJ11
T/F if you take an antacid tablet, the ph in your stomach will increase. this means your stomach juice becomes more acidic.
If you take an antacid tablet, the ph in your stomach will increase. this means your stomach juice becomes more acidic - False
The stomach's pH will rise if a person takes an antacid pill. Antacids neutralise excess stomach acid to treat conditions like gastroesophageal reflux disease, heartburn, and acid indigestion. They usually consist of elements such as calcium carbonate, magnesium or aluminium hydroxide; when coupled with stomach acid, these elements react to form salts and water.
Antacids reduce the acidity of the stomach contents by raising the pH level and neutralising the stomach's acid. This can aid in reducing the symptoms brought on by excessive acid production. Therefore, it is untrue that taking an antacid increases the acidity of the stomach liquid.
Read more about stomach on:
https://brainly.com/question/29812006
#SPJ4
Questions 7-10 refer to the following types of energy. (A) Activation energy (B) Free energy (C) Ionization energy (D) Kinetic energy (E) Lattice energy 7. The energy required to convert a ground-state atom in the gas phase to a gaseous positive ion __________ 8. The energy change that occurs in the conversion of an ionic solid to widely separated gaseous ions ___________ 9. The energy in a chemical or physical change that is available to do useful work ___________ 10. The energy required to form the transition state in a chemical reaction ___________
Answer:
7. Ionization energy
8. Lattice energy
9. Free energy
10. Activation energy
Explanation:
I. Ionization energy: The energy required to convert a ground-state atom in the gas phase to a gaseous positive ion. Thus, it is the minimum energy required to remove or detach an electron from a neutral atom in a gaseous state. Generally, atoms with relatively large atomic radii tend to have a low ionization energy.
II. Lattice energy: The energy change that occurs in the conversion of an ionic solid to widely separated gaseous ions. This ultimately implies that, it is the energy generated during the conversion of an ionic solid into gaseous ions and as such is a measure of the cohesive force binding the ions of an ionic compound using the Born-Haber cycle.
III. Free energy: the energy in a chemical or physical change that is available to do useful work. Thus, it is a thermodynamic quantity that measures the maximum capacity of a system to do work at constant temperature and pressure.
IV. Activation energy: The energy required to form the transition state in a chemical reaction. When the activation energy of a reaction is low, the rate of the reaction would be faster. Therefore, an enzyme speeds or catalyzes the rate of a reaction by lowering its activation energy.
a different student trying to determine if a different white solid is a true hydrate heats the sample and observes water droplets on the side of the test tube. the residue obtained is brownish and dissolves in water, producing a solution that is dark reddish-brown. is this a true hydrate? provide full reasoning.
Based on the observations described, it is likely that the white solid is a true hydrate.
Water droplets on the side of the test tube: When heating a hydrate, the water molecules trapped within the crystal lattice are released as vapor. The presence of water droplets on the side of the test tube indicates that water was indeed released during the heating process.
Brownish residue: The brownish residue obtained after heating the solid suggests that the white solid might contain a transition metal ion. Transition metal ions can form complex compounds that exhibit different colors, including brown.
Dissolving in water: The brownish residue dissolves in water, indicating that it is soluble in the solvent.
Dark reddish-brown solution: The solution obtained after dissolving the brownish residue is described as dark reddish-brown. This color could be attributed to the formation of a complex compound between the transition metal ion in the residue and the water or other substances present in the solution.
Based on the observations of water droplets upon heating, the brownish residue that dissolves in water, and the resulting dark reddish-brown solution, it is likely that the white solid is a true hydrate.
The presence of water droplets and the dissolution of the residue suggest that water was released from the solid during heating, indicating the presence of water molecules within the crystal lattice.
The color change to brownish and the subsequent dark reddish-brown solution point towards the involvement of a transition metal ion, possibly forming a complex compound.
To know more about hydrate visit:
https://brainly.com/question/29188417
#SPJ11
how many grams is 3.49 moles NaCl
Answer:
m = 204.16 grams
Explanation:
Given that,
No. of moles, n = 3.49
Molar mass of NaCl, M = 58.5 g/mol
We need to find the mass of 3.49 moles NaCl. We know that,
[tex]n=\dfrac{m}{M}\\\\m=n\times M\\\\m=3.49 \times 58.5\\\\m=204.16\ g[/tex]
So, there are 204.16 grams in 3.49 moles NaCl.
The mass in grams of 2.6 x 10^22 chlorine atoms is
a.4.4
b.0.76
c.1.5
d.11
Which planet could support human life
Answer:
D
Explanation:
It states that D has oxygen, and is closer to the Sun.
Hope this helped, and please mark as Brianliest <3
Answer:
I am pretty sure it is B
Explanation:
The others would either burn u like a crispy chicken nugget or freeze you like a popsicle
molecular mass meaning in chemistry?
Answer:
Molecular mass is a number equal to the sum of the atomic masses of the atoms in a molecule.
Explanation:
The molecular mass gives the mass of a molecule relative to that of the 12 C atom, which is taken to have a mass of 12. Hence why Molecular mass is a number equal to the sum of the atomic masses of the atoms in a molecule.
how did the report on the topic of climate change help the general public relate to the topic?
Answer:
Report of the climate change can help the people. As when people wants to go for picnics or somewhere else. They did not have any idea that what will be the climate when they go. Report of climate change help him to choose the right time for going on picnics or somewhere else.
Answer:
The report mentioned ways that people’s lives may change because of climate change, such as rising sea levels, reduced crop efficiency, and heat waves. This information may encourage the public to change the way they use energy, for example how they heat their homes or power their cars.
Explanation:
Describe the work being done by Robin Reineke and her team.
Answer:
They study different way people have died or could die to better aid investigators.
Explanation:
Heat is the measure of the average kinetic energy of particles; temperature is the measure of the transfer of thermal energy .
true or false
Which species will have the highestconcentration in a 0.25 M aq sol of boric acid?Ka1 = 7.3 x 10-10Ka2 = 1.8 x 10-13Ka3 = 1.6 x 10-14A. H3BO3B. H2BO3-C. HBO32-D. BO33-E. H+
In a 0.25 M aqueous solution of boric acid, the species with the highest concentration would be H_{3}BO_ 3}^{-} option B.
Boric acid (H_{3}BO_{3}) is a weak acid that can undergo multiple ionization steps. The given equilibrium constants (Ka) provide information about the ionization reactions. The first ionization reaction of boric acid is as follows:
[tex]H_{3}BO_{3}[/tex] ⇌ H^{+}+ H_{3}BO_ 3}^{-}
Ka1 = 7.3 x 10^-10
The second ionization reaction is:
[tex]H_{3}BO_ 3}^{-}[/tex] ⇌H^{+} + H_{3}BO_ 3}^{-2}
Ka2 = 1.8 x 10^-13
The third ionization reaction is:
H_{3}BO_ 3}^{-2} ⇌ H+ + [tex]BO_{3} ^{-3}[/tex]
Ka3 = 1.6 x [tex]10^{-14}[/tex]
To determine the species with the highest , we need to compare the equilibrium constants. The larger the Ka value, the more the reaction favors the dissociation of the species.
Based on the given Ka values, the second ionization reaction (H2BO3- ⇌ [tex]H^{+}[/tex] + H_{3}BO_ 3}^{-2}) has the highest Ka value (1.8 x 10^-13). This indicates that the concentration of H_{3}BO_ 3}^{-} in the solution would be higher compared to the other species. Therefore, option B, H_{3}BO_ 3}^{-}, would have the highest concentration in a 0.25 M aqueous solution of boric acid.
Learn more about ionization here: https://brainly.com/question/1602374
#SPJ11
What is a buffer used for?
A. To limit the pH change in a solution
B. To prevent an acid from dissociating
C. To neutralize the pH of a solution
D. To prevent a salt from dissolving
A buffer is primarily used to limit the pH change in a solution. Option A is correct.
A buffer is the solution which contains the weak acid and its conjugate base or weak base and its conjugate acid. It is designed to resist changes in pH when small amounts of acid or base are added to it.
When an acid or base is added to a buffer solution, the buffer components react with the added ions to minimize the impact on the solution's pH. If an acid is added, the buffer will react with the acid by accepting the H⁺ ions. If a base is added, the buffer will react with the base by donating H⁺ ions. In both cases, the buffer helps maintain the pH at a relatively stable level.
To prevent an acid from dissociating, is not accurate. A buffer does not prevent an acid from dissociating. In fact, the acid in a buffer solution is necessary to provide the conjugate base and maintain the buffer's pH buffering capacity.
To neutralize the pH of a solution, is also not accurate. A buffer does not neutralize the pH of a solution to a particular value. Instead, it resists significant changes in pH when small amounts of acid or base are added.
To prevent a salt from dissolving, is unrelated to the purpose of a buffer. A buffer is not used to prevent the dissolution of salts.
Hence, A. is the correct option.
To know more about buffer here
https://brainly.com/question/31847096
#SPJ2
How do plants respond to seasonal changes
Answer
Plants can respond to the change of season by losing their leaves, flowering, or breaking dormancy. Plants go through seasonal changes after detecting differences in day length.
Explanation:
what is the difference between corrosion and rusting
Answer:
Corrosion is the process of deterioration of materials as a result of chemical, electrochemical or other reactions. Rusting is a part of corrosion and is a chemical process which results in the formation of red or orange coating on the surface of metals. ... Rust or rusting can affect only iron and its alloys.
Explanation:
Which has the highest heat capacity? (Values of heat capacities and calculations are unnecessary). a. 1000 L of liquid water b. 10 g of sand c. 1 g of Iron d. 5g of glass
Option a, 1000 L of liquid water, is likely to have the highest heat capacity among the given options.
The heat capacity of a substance refers to the amount of heat energy required to raise the temperature of that substance by a certain amount. In general, substances with higher molar masses and larger numbers of atoms or molecules tend to have higher heat capacities.
Given the options provided:
a. 1000 L of liquid water has a higher heat capacity compared to the other options because water has a relatively high molar mass and specific heat capacity.
b. 10 g of sand generally has a lower heat capacity compared to water since sand has a lower molar mass and specific heat capacity.
c. 1 g of iron has a moderate heat capacity. While iron has a higher molar mass compared to sand, it typically has a lower specific heat capacity than water.
d. 5 g of glass generally has a lower heat capacity compared to water, as glass has a lower molar mass and specific heat capacity.
Therefore, option a, 1000 L of liquid water, is likely to have the highest heat capacity among the given options.
Learn more about Specific heat capacity from the link given below.
https://brainly.com/question/1105305
#SPJ4
given the following balanced equation, if the rate of o2 loss is 2.42 × 10–3 m/s, what is the rate of formation of so3? 2 so2 (g) o2 (g) → 2 so3 (g)
a.1.21 x 10-3 M/S b.1.19 x 10-3 M's c.6.05 x 10-2 M's d.4.84 x 10-3 M/s
The rate of formation of SO₃ is 4.84 × 10⁻³ m/s. The correct option is d. 4.84 × 10⁻³ M/s.
To determine the rate of formation of SO₃, we need to consider the stoichiometry of the balanced equation. The coefficient of SO₃ is 2, which means that for every 1 mole of O₂ reacted, 2 moles of SO₃ are formed.
Given that the rate of O₂ loss is 2.42 × 10⁻³ m/s, we can use the stoichiometry to find the rate of formation of SO₃.
Rate of formation of SO₃ = (2 moles SO₃ / 1 mole O₂) × (2.42 × 10⁻³ m/s)
Rate of formation of SO₃ = 4.84 × 10⁻³ m/s
Therefore, the rate of formation of SO₃ is 4.84 × 10⁻³ m/s. The correct option is d. 4.84 × 10⁻³ M/s.
Learn more about rate of formation from the link given below.
https://brainly.com/question/27549044
#SPJ4
Sven perform this reaction with 15.0 grams of sodium sulfate and an excess of iron (III) phosphate to make iron (III) sulfate and sodium phosphate. In the actual experiment, 10.0 grams of sodium phosphate are experimentally made, what is the percent yield?
2FePO4+3Na2SO4-->Fe2(SO4)3+2Na3PO4
Answer:
85.5%
Explanation:
To get the experimental value, you need to convert 15.0 grams of Na2SO4 to grams of Na3PO4. You do this with stoichiometry.
Convert grams of Na2SO4 to moles with molar mass. Then convert to moles of Na3PO4 with the mole-to-mole ratio according to the balanced chemical equation. Then convert moles of Na3PO4 to grams with the molar mass.
15.0 g Na2SO4 x (1 mol/142.04 g) x (2 Na3PO4/3Na2SO4) x (163.94 g/1 mol) = 11.7 g Na3PO4
Percent Yield = (actual value/experimental value) x 100
Actual Value = 10.0 g
Experimental Value = 11.7 g
10.0g/11.7 g = 85.5%
what is a phase diagram? what is a phase diagram? a phase diagram is simply a map of the phase of a substance as a function of volume (on the y-axis) and number molecules (on the x-axis). a phase diagram is simply a map of the phase of a substance as a function of pressure (on the y-axis) and number molecules (on the x-axis). a phase diagram is simply a map of the phase of a substance as a function of pressure (on the y-axis) and temperature (on the x-axis). a phase diagram is simply a map of the phase of a substance as a function of volume (on the y-axis) and pressure (on the x-axis).
A phase diagram is a graphical representation or map that shows the different phases (solid, liquid, and gas) of a substance as a function of pressure and temperature. It provides valuable information about the conditions under which a substance exists in each phase or undergoes phase transitions.
In a phase diagram, pressure is typically represented on the y-axis, and temperature is represented on the x-axis. The diagram is divided into regions corresponding to different phases, and boundaries or lines separating these regions represent phase transitions.
The phase diagram allows us to determine the conditions at which a substance can exist as a solid, liquid, or gas, and it provides insights into the effects of temperature and pressure on the phase behavior of the substance.
It helps in understanding processes such as melting, boiling, and sublimation and provides a useful tool in various fields including chemistry, physics, and materials science.
To know more about the phase diagram refer here :
https://brainly.com/question/31948241#
#SPJ11
A copper coin with a mass of 6.30 grams changes temperature in the sunshine from 20.0°C to 32.0°C. How much energy is transferred? The specific heat capacity of copper is 0.377 joules/gram degree Celsius. Express your answer to three significant figures.
The amount of energy transferred to the coin is
joules.
Answer:
q = mC∆T
q = heat = ?
m = mass = 6.30 g
C = specific heat = 0.385 J/g/deg
∆T = change in temperature = 32-20 = 12º
q = ((6.30 g)(0.385 J/g/deg)(12 deg) = 29.1 J (to 3 significant figures)
Explanation:
Anyone know how to do this? It’s for Chemisty
URGENT LOOK AT PICTURE
look at the thing and choose all that matches
Answer:
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
BRAINLIEST PLEASE
Calculate the molarity of each aqueous solution with the given amount of Nacl58.44 and final volume. A .3.30 in 0.340L,6.00mol in 550ml,0.0160mol in 9.00ml
Answer:
For A: The molarity is the solution 9.706 M
For B: The molarity of the solution is 10.91 M.
For C: The molarity of the solution is 1.78 M.
Explanation:
Molarity is defined as the amount of solute expressed in the number of moles present per liter of solution. The units of molarity are mol/L.
The formula used to calculate molarity:
[tex]\text{Molarity of solution}=\frac{\text{Number of moles of solute}}{\text{Volume of solution (L)}}[/tex] ......(1)
For A:
Number of moles = 3.30 moles
Volume of solution = 0.340 L
Plugging values in equation 1:
[tex]\text{Molarity of solution}=\frac{3.30 mol}{0.340 L}=9.706 mol/L[/tex]
For B:
Number of moles = 6.00 moles
Volume of solution = 550 mL = 0.550 L (Conversion factor: 1 L = 1000 mL)
Plugging values in equation 1:
[tex]\text{Molarity of solution}=\frac{6.00 mol}{0.550 L}=10.91 mol/L[/tex]
For C:
Number of moles = 0.0160 moles
Volume of solution = 9.00 mL = 0.009 L
Plugging values in equation 1:
[tex]\text{Molarity of solution}=\frac{0.0160 mol}{0.009 L}=1.78 mol/L[/tex]
Hydrated transition metal ions typically produce solutions that are _____ (a) acidic. (b) basic. (c) neutral (d) strongly basic. (e) strongly acidic.
Water molecules that surround the metal ions act as weak Brønsted-Lowry acids and donate protons to the solution, increasing its acidity.
Hydrated transition metal ions typically produce solutions that are acidic. Transition metal ions are elements from the transition series that are capable of forming coordination complexes that have characteristic colors, and they exhibit a wide range of oxidation states and show various magnetic properties.In addition, when transition metals react with water, they create hydrated metal ions, which produce acidic solutions. This is because water molecules that surround the metal ions act as weak Brønsted-Lowry acids and donate protons to the solution, increasing its acidity.Therefore, the correct answer is (a) acidic.
Learn more about Brønsted-Lowry acids here:
https://brainly.com/question/32276007
#SPJ11
A buoy bobs up and down in the ocean. The waves have a wavelength of
2.5 m, and they pass the buoy at a speed of 4.0 m/s. What is the frequency
of the waves?
A. 1.6 Hz
B. 10 Hz
C. 6.5 Hz
D. 1.5 Hz
Answer:
c
Explanation:
Which species functions as the oxidizing agent in the following reduction-oxidation reaction? ZnO(s) + C(s) → Zn(s) + CO(g) A) ZnO(s) B) C(s) C) CO(g) D) Zn(s)
In the following reduction-oxidation reaction; ZnO(s) + C(s) → Zn(s) + CO(g), the species which functions as the oxidizing agent is option (B) C(s).
In the reaction ZnO(s) + C(s) → Zn(s) + CO(g), C(s) gains oxygen and goes from being a carbon atom to a carbon dioxide molecule which contains two oxygen atoms. Therefore, C(s) has been oxidized. Carbon is being oxidized in the above reaction because it has gained oxygen.
The term oxidation refers to the loss of electrons by an atom or molecule. Oxidation is a type of chemical reaction in which a substance loses electrons to another substance. The oxidation process usually occurs with a substance's interaction with oxygen.
Therefore, the correct answer is option B) C(s).
Learn more about the reduction-oxidation reaction here:
https://brainly.com/question/19528268
#SPJ11
Which noble gas is expected to show the largest deviations from the ideal gas behavior? A) helium B) neon C) argon D) krypton E) xenon why
he molar volume of a gas at STP is __________ L.
A) 0.08206
B) 62.36
C) 1.00
D) 22.4
E) 14.7
The noble gas expected to show the largest deviations from the ideal gas behavior is Xenon (Xe).The molar volume of a gas at STP is 22.4 L. This is because 1 mole of gas occupies 22.4 L of volume at 0°C and 1 atm pressure
The ideal gas behavior is only possible at low pressures and high temperatures. A gas can be assumed to be ideal if its atoms or molecules are far apart and there is no interaction between them. Since noble gases are monatomic gases and their atoms are quite far apart, they are expected to behave like ideal gases.However, xenon is the largest of all noble gases, and its atoms have large sizes and masses. As a result, they experience stronger attractive forces between atoms than the other noble gases, leading to deviations from ideal gas behavior.The molar volume of a gas at STP is 22.4 L. This is because 1 mole of gas occupies 22.4 L of volume at 0°C and 1 atm pressure. Hence, the correct answer is option D) 22.4.
Learn more about noble gas here:
https://brainly.com/question/32007931
#SPJ11
Draw the predominant product(s) of the following reactions including stereochemistry when it is appropriate. CH3-CEC-CH3 + 2HBr . Consider EZ stereochemistry of alkenes. • Do not show stereochemistry in other cases. • If no reaction occurs, draw the organic starting material. Draw one structure per sketcher. Add additional sketchers using the drop-down menu in the bottom right corner. • Separate multiple products using the sign from the drop- down menu. ChemDoodle
The product of the reaction between [tex]CH_{3}[/tex]-CH=[tex]CH_{2}[/tex] and HBr is 2-bromo-3-methylbutane.
The reaction proceeds through the addition of a proton from HBr to the double bond, followed by the addition of a bromide ion.
The addition of the proton is stereospecific, and the bromide ion will add to the carbon atom that is least substituted by hydrogen. In this case, the carbon atom that is least substituted by hydrogen is the carbon atom that is attached to two hydrogen atoms.
Therefore, the bromide ion will add to the carbon atom that is attached to the double bond and the methyl group. The product of the reaction is 2-bromo-3-methylbutane.
here is the predominant product of the reaction of [tex]CH_{3}CHCH=CH-CH_{3}[/tex] with HBr:
Know more about stereospecific reaction here:
brainly.com/question/30849463
#SPJ4
The complete question is:
Draw the predominant product(s) of the following reactions including stereochemistry when appropriate. CH CH CH -CEC-H HBr Consider EIZ stercochemistry of alkenes. Do not show stereochemistry in other cases If no reaction occurs_ raw the organic starting material. Draw one stnicture per sketcher Add additional sketchers using the drop down menu in the bottom right corner Separate multiple products using the sign from the drop-down menu: ChemDoodle Submit Answver Retry Entire Group more cirovp attempts remaining
What volume of 0.062 M HCl is needed to react to completely neutralize 19.4 mL of 0.050 M Ba(OH)2? *
Answer:
31.3 mL
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
2HCl + Ba(OH)₂ —> BaCl₂ + 2H₂O
From the balanced equation above,
The mole ratio of the acid, HCl (nₐ) = 2
The mole ratio of the base, Ba(OH)₂ (n₆) = 1
Finally, we shall determine the volume of the acid need for the reaction as follow:
Molarity of acid, HCl (Mₐ) = 0.062 M
Mole ratio of the acid, HCl (nₐ) = 2
Volume of base, Ba(OH)₂ (V₆) = 19.4 mL
Molarity of base, Ba(OH)₂ (M₆) = 0.050 M
Mole ratio of the base, Ba(OH)₂ (n₆) = 1
Volume of acid, HCl (Vₐ) =?
MₐVₐ / M₆V₆ = nₐ / n₆
0.062 × Vₐ / 0.050 × 19.4 = 2/1
0.062 × Vₐ / 0.97 = 2
Cross multiply
0.062 × Vₐ = 0.97 × 2
0.062 × Vₐ = 1.94
Divide both side by 0.062
Vₐ = 1.94 / 0.062
Vₐ = 31.3 mL
Thus, the volume of the acid needed is 31.3 mL
What do the horizontal portions of the graph represent? When heat is added to or removed from the substance and the temperature remains the same, where is the thermal energy going? Why?
!!MARKING BRAINLIEST!! Please help this is due at midnight!! No websites please just help me! :(
Answer:
I'll do the first one for you. The reason why I'm not going to do the rest is because this is pretty simple stuff. I'll explain how I got the answer, please read it ^^ the rest of the problems should be a breeze.
1. 5.454285714285714 liters, or approx. 5.45 liters
Explanation:
P1V2 = P2V2
P1 refers to the original pressure. V1 refers to the original volume, or the amount of space the gas takes up.
P2 and V2 refer to the final pressure or volume, accordingly.
You insert the values into the equation, like so:
(8.3)(46) = (70)(x)
Now, multiply.
381.8 = 70x
Use inverse operations to find the value of x. Divide 381.8 by 70 to isolate x.
381.8/70 = x
5.454285714285714 = x
The volume of the gas when the pressure is increased to 70.0 mm Hg is approximately 5.45 liters. Don't forget about the units at the end, when you write your final answer.
Important! When pressure increases, volume decreases, and vice versa. Volume and pressure for gases are inversely proportional. So even though the pressure increased, that doesn't mean the volume increases, too.
You can check your answers easily!
Just multiply your final answer by its corresponding pressure or volume and compare it to the other. I hope that made sense. Like so:
5.454285714285714 x 70 = 381.8
8.3 x 46 = 381.8
That makes P1V2 DOES equal P2V2, and your answer is correct.
I hope this helped in time for you to submit it before the deadline! Good luck.
Tips!
For #2: I'm pretty sure the mentioning of the temperature (25.0 °C) doesn't matter. You can ignore it, it won't affect your calculations.
For #4: the standard pressure in mm Hg (millimeters of mercury) is 760 mm Hg. That's your P2.