Answer:
Q = 2640.96 J
Explanation:
Given data:
Mass of He gas = 10.7 g
Initial temperature = 22.1°C
Final temperature = 39.4°C
Heat absorbed = ?
Solution:
Specific heat capacity:
It is the amount of heat required to raise the temperature of one gram of substance by one degree. Specific heat capacity of He is 14.267 J/g.°C
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 39.4°C - 22.1°C
ΔT = 17.3°C
Q = 10.7 g× 14.267 J/g.°C × 17.3°C
Q = 2640.96 J
. The level of mercury in a stream was suspected to be above the minimum considered safe (1 part per billion by weight). And analysis indicated that the concentration was 0.68 parts per billion. Assume a density of 1.0 g/mL and calculate the molarity of mercury in the stream.
Answer:
3.39x10⁻⁹ M
Explanation:
Let's assume we have 1 mL of the stream. With a density of 1.0 g/mL, we would have 1 g of the stream.
Now we calculate the mass of mercury present in 1 g of the stream, using its given concentration (0.68 ppb):
ppb = ng Mercury / g stream0.68 ppb = ng Hg / 1 gMass of mercury = 0.68 ngNow we convert that mass into moles, using mercury's atomic mass:
0.68 ng = 0.68 x 10⁻⁹ g0.68 x 10⁻⁹ g ÷ 200.59 g/mol = 3.39x10⁻¹² molFinally we calculate the molarity of mercury, as we know that there are 3.39x10⁻¹² Hg moles in 1 mL of the stream:
1 mL = 0.001 LMolarity = 3.39x10⁻¹² mol / 0.001 L = 3.39x10⁻⁹ M
Enter your answer in the provided box. Muriatic acid, an industrial grade of concentrated HCl, is used to clean masonry and cement. Its concentration is 11.7 M. For routine use, a diluted solution of 3.50 M is prepared. How many milliliters of 3.50 M muriatic acid solution contain 32.8 g of HCl
Answer:
257 mL
Explanation:
Step 1: Given data
Concentration of the muriatic acid solution used (C): 3.50 M (3.50 mol/L)Mass of HCl (m): 32.8 gStep 2: Calculate the moles (n) corresponding to 32.8 g of HCl
The molar mass of HCl is 36.46 g/mol.
32.8 g × 1 mol/36.46 g = 0.900 mol
Step 3: Calculate the volume (V) of solution required
We will use the following expression.
C = n/V
V = n/C
V = 0.900 mol/(3.50 mol/L)
V = 0.257 L = 257 mL
A geochemist in the field takes a 36.0 mL sample of water from a rock pool lined with crystals of a certain mineral compound X. He notes the temperature of the pool, 170 C, and caps the sample carefully. Back in the lab, the geochemist filters the sample and then evaporates all the water under vacuum. Crystals of are left behind. The researcher washes, dries and weighs the crystals. They weigh 3.96 g. Using only the information above, can you calculate the solubility of X in water at 17.0C? If you said yes, calculate it.
Answer:
Yes, 0.11g/mL is the solubility of X in water at 17.0°C.
Explanation:
As the sample of water has crystals around it, the solution is oversaturated at 17.0°C. The water contains the maximum amount of X at 17.0°C, this concentration is called solubility. Thus, yes, we can calculate solubility in water at 17.0°C
The concentration of the crystals is 3.96g in 36.0mL, that is:
3.96g / 36.0mL =
0.11g/mL is the solubility of X in water at 17.0°CANSWER QUICK !!!
How many grams of hydrogen gas will be produced if you start with 15.0 grams of zinc and an excess amount of HCI?
balanced equation:
Zn + 2HCI = ZnCl2 + H2
Answer:
0.48g
Explanation:
Given parameters:
Mass of zinc = 15g
Unknown:
Mass of hydrogen gas = ?
Solution:
To solve this problem, we need to state the balanced reaction expression first;
Zn + 2HCl → ZnCl₂ + H₂
Find the number of moles of Zn;
Number of moles = [tex]\frac{mass}{molar mass}[/tex] = [tex]\frac{15}{63.4}[/tex] = 0.24mol
From the balanced reaction expression;
1 mole of Zn will produce 1 mole of H₂
0.24mole of Zn will produce 0.24mole of hydrogen gas
Mass of hydrogen gas = number of moles x molar mass
= 0.24 x (2 x 1)
= 0.48g
Consider this reaction: At a certain temperature it obeys this rate law. rate Suppose a vessel contains at a concentration of . Calculate how long it takes for the concentration of to decrease by . You may assume no other reaction is important. Round your answer to significant digits.
This question is incomplete, the complete question is;
Consider this reaction:
2H₃PO₄(aq) → p₂o₅(aq) + 3H₂O(aq)
At a certain temperature it obeys this rate law.
rate = ( 46.65 M⁻¹.s⁻¹) [ H₃PO₄ ]²
Suppose a vessel contains H₃PO₄ at a concentration of 0.660 M .
Calculate how long it takes for the concentration of H₃PO₄ to decrease to 20.0% of its initial value .
You may assume no other reaction is important.
Round your answer to significant digits.
Answer:
time taken is 8.574 × 10⁻⁴ s
Explanation:
Given that;
rate = k[ H₃PO₄ ]²
rate constant k = 46.65 M⁻¹.s⁻¹)
Initial concentration A₀ = 0.660 M { which will be 100%}
final concentration At = 20%
for the concentration of H₃PO₄ to decrease to 20.0% of its initial value = ?
we know that;
rate constant k = 1/t [ 1/At - 1/A₀ ]
we substitute
46.65 = 1/t [ 1/20 - 1/100 ]
46.65 = 1/t [ 0.04 ]
46.65 = 0.04/t
46.65t = 0.04
t = 0.04 / 46.65
t = 0.0008574 ≈ 8.574 × 10⁻⁴ s
Therefore, time taken is 8.574 × 10⁻⁴ s
Halogenated compounds are particularly easy to identify by their mass spectra because chlorine and bromine occur naturally as mixtures of two abundant isotopes. Chlorine occurs as 35Cl (75.8%) and 37Cl (24.2%); Bromine occurs as 79Br (50.7%) and 81Br (49.3%); Boron compounds also stand out owing to the two isotopes 10B (19.9%) and 11B (80.1%).
Required:
a. At what masses do the molecular ions occur for the following formulas?
b. What are the relative percentages of each molecular ion?
Answer:
Explanation:
From the given information:
The compound in question here is [tex]\mathbf{C_2H_5Br}[/tex]
The molar mass of [tex]\mathbf{C_2H_5Br}[/tex] with 79 Br is;
= (2 × 12) + (1 × 5) + 79
= 108 g/mol
The molar mass of [tex]\mathbf{C_2H_5Br}[/tex] with 81 Br is:
= (2 × 12) + (1 × 5) + 81
= 110 g/mol
Thus, the mass at which the molecular ions occurs are:
108 and 110.
The relative percentage of mass 108 occurred at 50.7%
The relative percentage of mass 110 occurred at 49.3%
Which statement correctly describes ionic bonds? Multiple Choice An ionic bond only forms between two atoms of the same element. Ionic bonds usually form between electrically neutral, stable atoms. An ionic bond is the electrostatic force that holds ions together when they form bonds. All of the answer choices are correct.
Answer:
An ionic bond is the electrostatic force that holds ions together when they form bonds
Explanation:
An ionic bond is formed when a metal looses electron(s) to a non metal leading to the formation of a positive ion and a negative ion.
An ionic compound is actually an ion pair, the ions are held together by strong electrostatic forces.
This strong electrostatic force that holds the ion pair together in ionic compounds is what we commonly call the IONIC BOND.
Answer:
An ionic bond is the electrostatic force that holds ions together when they form bonds
Explanation:
I took this test and it was the correct answer :)
Photosynthesizing organisms use ____
to produce glucose.
Answer: Photosynthesizing organisms use carbon dioxide and water to produce glucose.
Explanation:
Photosynthesis is a phenomenon in which green plants containing chlorophyll use sunlight as a source of energy to convert carbon dioxide and water to form glucose and oxygen.
Photosynthesis is the process used by plants, algae and certain bacteria to convert energy from sunlight and turn it into chemical energy in the form of glucose which is used a s a source of energy by many organisms.
[tex]6CO_2+6H_2O\overset{sunlight}\rightarrow C_6H_{12}O_6+6O_2[/tex]
which type of bond involves 2 different metals?
A. ionic
B. Covalent
C.Metallic
D. Bonding would not occur
Answer:
iconic bond is the answer
I hope it helps you ✌
The 10x SDS gel electrophoresis buffer contains 250mM Tris HCl, 1.92M Glycine, and 1% (w/v) SDS. Buffers are always used at 1x concentration in the lab (unless specified otherwise in the protocol), so you will have to dilute the 10x buffer to 1x before use. What is the concentration of Tris and SDS in the 1x buffer
Answer:
25 mM Tris HCl and 0.1% w/v SDS
Explanation:
A 10X solution is ten times more concentrated than a 1X solution. The stock solution is generally more concentrated (10X) and for its use, a dilution is required. Thus, to prepare a buffer 1X from a 10X buffer, you have to perform a dilution in a factor of 10 (1 volume of 10X solution is taken and mixed with 9 volumes of water). In consequence, all the concentrations of the components are diluted 10 times. To calculate the final concentration of each component in the 1X solution, we simply divide the concentration into 10:
(250 mM Tris HCl)/10 = 25 mM Tris HCl
(1.92 M glycine)/10 = 0.192 M glycine
(1% w/v SDS)/10 = 0.1% w/v SDS
Therefore the final concentrations of Tris and SDS are 25 mM and 0.1% w/v, respectively.
What role do wolves play in the tundra?
Answer:
predator
Explanation:
Wolves, arctic foxes, and snowy owls are predators in the tundra.
Drag the tiles to the correct boxes to complete the pairs.
Match the descriptions with the types of blas.
selection bias
expectation bias
confirmation bias
contextual bias
paying more attention to evidence that
confirms one's hypothesis and ignoring
evidence that may discount it
to be swayed from one's conclusion by
additional information
coming to a conclusion before all the
evidence has been processed and therefore
unconsciously disregarding evidence to the
contrary
Answer:
Explanation:
here's the answer hope it helps! :)
How many moles of Fe2O3 are in 17.2g?
A - 1.23
B - 2.75
C - 0.239
D - 0.108
Answer:
C
Explanation:
0.10 moles of Fe[tex]_2[/tex]O[tex]_3[/tex] are in 17.2g. Therefore, the correct option is option D among all the given options.
What is iron(III) oxide?The inorganic chemical with both the formula Fe[tex]_2[/tex]O[tex]_3[/tex] is iron(III) oxide and ferric oxide. It is one of three major iron oxides, the other 2 including iron(II) oxide (FeO), which would be uncommon, and iron(II,III) oxides (Fe[tex]_2[/tex]O[tex]_3[/tex]), which naturally occurs as the mineral magnetite.
Acids have a high affinity for Fe[tex]_2[/tex]O[tex]_3[/tex] . Iron(III) oxide is commonly referred to as rust, and this name is appropriate to some extent because rust has certain features and has a comparable composition; nevertheless, in chemistry, colouration is classified under Hydrous ferric oxide.
mole = 17.2/ 159.69 =0.10moles
Therefore, the correct option is option D.
To know more about iron(III) oxide, here:
https://brainly.com/question/8834237
#SPJ2
As the food burned,
energy was
nergy. Thus, a
thermal
transformed intos
chemical
form of Select
nuclear
$ converted to a
form of
Select
energy.
Check
Answer:
I don't get it is it even a question?
I need help with answer 1 and 2 ASAP please!!
Answer:
1. B 2.B
Explanation:
Please help me on this
Why is it important to recognize the physical properties of the reactants in the chemical reaction that you will model in your culminating event project?
Chemical Changes
Chemical changes take place at the molecular level. A chemical change produces a new substance. Another way to think of it is that a chemical change accompanies a chemical reaction. Examples of chemical changes include combustion (burning), cooking an egg, rusting of an iron pan, and mixing hydrochloric acid and sodium hydroxide to make salt and water.
Physical Changes
Physical changes are concerned with energy and states of matter. A physical change does not produce a new substance, although the starting and ending materials may look very different from each other. Changes in state or phase (melting, freezing, vaporization, condensation, sublimation) are physical changes. Examples of physical changes include crushing a can, melting an ice cube, and breaking a bottle.
How to Tell Chemical & Physical Changes Apart
A chemical change makes a substance that wasn't there before. There may be clues that a chemical reaction took places, such as light, heat, color change, gas production, odor, or sound. The starting and ending materials of a physical change are the same, even though they may look different.
hope this helps
5 star and brainliest?
Dolphins have the same arm structure as wolves. What type of evidence for evolution does this represent?
A. DNA
B. vestigial structures
C.homologous structures
D. embryology
What is the difference between the grassland and savanna biomes?
A)Grassland biomes are closer to the equator and receive more rain.
B)Savanna biomes are closer to the equator and receive more rain.
C)Grassland biomes contain mostly grasses.
D)Savanna biomes contain mostly grasses.
Answer:
C)Grassland biomes contain mostly grasses.
Explanation:
The main differences between a savanna biome and a grassland is that grasslands biomes contain mostly grasses.
Savanna are made up of both grasses and shrubs.
Savanna are a mix of grasslands with some scattered trees in the area. Grasslands are open grass fields. They do not contain much trees as such. The savanna and grasslands are renowned for their fauna diversity of beasts.A 1.018 g sample pure platinum metal was reacted with HCl to form 1.778 g of a compound containing only platinum and chlorine. Determine the empirical formula of this "Pt-Cl" Compound.
Answer:
[tex]PtCl_4[/tex]
Explanation:
Hello!
In this case, since HCl and Pt react according to the following chemical equation:
[tex]HCl+Pt\rightarrow PtCl_x+H_2[/tex]
Whereas PtClx is the compound containing Pt and Cl; thus, since 1.018 g out of 1.778 g correspond to Pt and therefore 0.760 g to chlorine, so we determine the empirical formula of this compound by firstly computing the moles of each element:
[tex]n_{Pt}=1.018gPt*\frac{1molPt}{195.084gPt}=0.00522molPt\\\\\\n_{Cl}=0.760gCl*\frac{1molCl}{35.45gCl} =0.0214molCl[/tex]
Now, we divide the each moles by those of Pt as the fewest ones in order to compute their subscripts in the empirical formula:
[tex]Pt=\frac{0.00522}{0.00522}=1 \\\\Cl=\frac{0.0214}{0.00522} =4[/tex]
Thus, the required formula is:
[tex]PtCl_4[/tex]
Best regards!
a titanium bicycle frame displays 0.250 L of water and has a mass of 1.21kg. what is the density of the titanium on g/cm3?
Answer:
$4.49 g/cm3
Explanation:
Density=Mass/Volume
plzz put brainiest
What volume, in liters, would 88.9 grams of a substance occupy if it’s density is 2.38 g/mL
Answer:
V = 0.03735 mL
Explanation:
Given that,
Mass of a substance, m = 88.9 grams
Density of a substance, d = 2.38 g/mL
We need to find the volume occupied by the object. The density of an object is given by mass per unit volume.
[tex]d=\dfrac{m}{V}\\\\V=\dfrac{m}{d}\\\\V=\dfrac{88.9}{2.38}\\\\V=37.35\ mL\\\\V=0.03735\ L[/tex]
So, the volume of the substance is 0.03735 mL.
In the Energy and Specific Heat lab, what temperature should be recorded as the final temperature of the water when measuring the food sample?
A. The temperature of the water when the food sample is first lit
B. The temperature of the water when the food sample has finished burning completely.
C. The highest temperature the water reaches as the sample burns
D. The temperature of the water after the food sample ash has been removed
Answer:
B. The temperature of the water when the food sample has finished burning completely.
Explanation:
Heat or thermal energy is a form of energy that transfers from one object to another due to a temperature difference between the objects. The units for heat are joules or calories.
Calorimetry is the measurement of heat energy released or absorbed in a chemical reaction. A calorimeter is used in calorimetry. The calorimeter operates on the Law of Conservation of Energy which states that energy is never created or destroyed but is transformed from one form to another or between objects.
In food calorimetry, the energy released when food is burned is measured by recording the rise in temperature of water in a calorimeter when a given mass of a food sample is burned completely.
Energy can be calculated using the formula: Q = mc ∆T
where Q = the energy in joules or calories, m = the mass in grams, c = specific heat and ∆T = the change in temperature (final temperature - initial temperature).
The temperature of the water when the food sample has finished burning completely is taken as the final temperature of the water. The sample is allowed to smolder for sometime before recording the final water temperature. This is because the water temperature will continue to rise after the flame has gone out.
What are suspensions
Answer: suspensions are a mixture in which solute particles do not disolve. An example is oil and water, oil and water or even flour and water; oil can’t disolve in water
Answer:
Noun: a mixture in which particles are dispersed throughout the bulk of a fluid.
Adjective: the state of being dispersed in a fluid.
Explanation:
I used a dictionary lol
Which of the following is the poorest conductor of electricity?
Calcium (Ca)
Silicon (Si)
Fluorine (F)
Sodium (Na)
Cobalt (Co)
Answer:
Fluorine (F)
Explanation:
The poorest conductor of electricity from the given choices is fluorine. This is because fluorine is a non - metal.
Like other non - metals, fluorine does not conduct electricity.
Only metals are known to conduct electricity and heat readily.
Semi - metals like silicon will conduct electricity under specific condition.
The free mobile electrons in metals makes it easy for them propagate electricity
How do plate tectonics affect mountains?
Mountains outline plate tectonic boundaries.
Plate tectonics spreading can create mountains.
Plate tectonic collisions can create mountains.
Mountains provide evidence for plate tectonics.
Answer:
C. Plate tectonic collisions can create mountains.
Answer:
They can make them larger
Explanation:
They go up under a mountain and then the mountains rise up
Clear liquid is on top of the green liquid,green liquid is on top of the red liquid.What is the order of density of the liquids, from highest to lowest
Answer:
This indicates there will be the densest (heaviest) liquid on the bottom of the jar there will be the least dense (lightest) liquid on top. Syrup, glycerin, water, oil, and then alcohol would be on top of the order of liquids from hardest to lightest.
Identify the missing species in each nuclear equation. Replace the question marks with the appropriate integer or symbol. Be410⟶B510+Be410⟶B510+ β−10β−10 Si1434⟶P1534+Si1434⟶P1534+ Pt78192⟶Pt78192⟶ pp?+ 42????+ 24α pp?⟶Al1328+β−10
Answer:
1. ¹⁰₄Be ---> ¹⁰₅B + ⁰₋₁β
2. ³⁴₁₄Be ---> ³⁴₁₅P + ⁰₋₁β
3. ¹⁹²₇₈Pt -----> ¹⁹⁰₇₆Os + ⁴₂α
4. ²⁸₁₂Mg ---> ²⁸₁₃Al + ⁰₋₁β
Explanation:
1. In the first equation, Beryllium-10 isotope undergoes beta-decay, emitting a beta-particle to form boron-10 isotope. The balanced nuclear equation is given below:
¹⁰₄Be ---> ¹⁰₅B + ⁰₋₁β
2. In this reaction, silicon-34 isotope undergoes beta-decay, emitting a beta-particle to form phosphorus-34 isotope. The balanced nuclear equation is given below:
³⁴₁₄Be ---> ³⁴₁₅P + ⁰₋₁β
3. In this equation, platinum-192 isotope undergoes alpha-particle decay emitting an alpha-particle to form osmium-190 isotope. The balanced nuclear equation is given below:
¹⁹²₇₈Pt -----> ¹⁹⁰₇₆Os + ⁴₂α
4. In this equation, magnesium-28 isotope undergoes beta-decay, emitting a beta-particle to form aluminum-28 isotope. The balanced nuclear equation is given below:
²⁸₁₂Mg ---> ²⁸₁₃Al + ⁰₋₁β
Calculate the mass of butane needed to produce 99.0 g of carbon dioxide.
Express your answer to three significant figures and include the appropriate units.
Answer:
32.7 g
Explanation:
Step 1: Write the balanced combustion reaction
C₄H₁₀ + 6.5 O₂ ⇒ 4 CO₂ + 5 H₂O
Step 2: Calculate the moles corresponding to 99.0 g of CO₂
The molar mass of CO₂ is 44.01 g/mol.
99.0 g × 1 mol/44.01 g = 2.25 mol
Step 3: Calculate the moles of C₄H₁₀ needed to produce 2.25 moles of CO₂
The molar ratio of C₄H₁₀ to CO₂ is 1:4. The moles of C₄H₁₀ needed are 1/4 × 2.25 mol = 0.563 mol.
Step 4: Calculate the mass corresponding to 0.563 moles of C₄H₁₀
The molar mass of C₄H₁₀ is 58.12 g/mol.
0.563 mol × 58.12 g/mol = 32.7 g
Based on the following chemical equation how many hydrogen atoms are present in the products side?
N2 + 3H2 ----> 2NH3
Question 2 options:
5
3
6
1
The number of Hydrogen atoms = 6 atoms
Further explanationGiven
Reaction
N₂ + 3H₂ ⇒ 2NH₃
Required
The number of Hydrogen atoms
Solution
The reaction coefficient of a chemical equation shows the mole ratio of the reacting compound.
On a compound the reaction coefficient indicates the number of molecules
Whereas the subscript after the atom shows the number of atoms in that compound
Product from the reaction : 2NH₃
Number of H-atoms :
= 2 x 3
= 6 atoms