Answer:
Explanation:
a )
Average reaction rate between 0 and 1500s
Time duration = 1500 s
moles reacted = .184 - .016 = .168 moles
Moles reacted per second = .168 / 1500
= 112 x 10⁻⁶ moles /s
b )
Average reaction rate between 200 and 1200s
Time duration = 1000 s
moles reacted = .129 - .019 = .11 moles
Moles reacted per second = .11 / 1000
= 110 x 10⁻⁶ moles /s
c )
the instantaneous rate of the reaction at t=800s
We shall assume that between 500 s and 1200 s , rate of reaction is uniform
rate between 500 and 1200
Time duration = 700 s
moles consumed = .069 - .019 = .05 moles
Rate of reaction = .05 / 700
= 71 .4 x 10⁻⁶ moles / s
This will also be instantaneous rate of reaction at t = 800 s .
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]
Liquid hexane will react with gaseous oxygen to produce gaseous carbon dioxide and gaseous water . Suppose 64. g of hexane is mixed with 72.0 g of oxygen. Calculate the maximum mass of carbon dioxide that could be produced by the chemical reaction. Be sure your answer has the correct number of significant digits.
Answer:
45.7g of CO₂ is the maximum amount of carbon dioxide that could be produced.
Explanation:
Hexane, C₆H₁₄, reacts with O₂ to produce H₂O and CO₂ as follows:
C₆H₁₄ + 13/2O₂ → 7H₂O + 3CO₂
Where 1 mole of hexane reacts with 13/2 moles of O₂.
To solve this question we need to convert the mass of each reactant to moles in order to find the limiting reactant. With limiting reactant we can find the maximum amount of CO₂ produced:
Moles C₆H₁₄ -Molar mass: 86.18g/mol-:
64g C₆H₁₄ * (1mol / 86.18g) = 0.7426 moles C₆H₁₄
Moles O₂ -Molar mass: 32g/mol-:
72.0g O₂ * (1mol / 32g) = 2.25 moles O₂
For a complete reaction of 2.25 moles of O₂ are required:
2.25 moles O₂ * (1mol C₆H₁₄ / 13/2 moles O₂) = 0.346 moles of C₆H₁₄
As there are 0.7426 moles of C₆H₁₄, C₆H₁₄ is the excess reactant and:
Oxygen is limiting reactant.
The maximum moles of CO₂ that could be produced are:
2.25 moles O₂ * (3mol CO₂ / 13/2 moles O₂) = 1.038 moles CO₂
In grams:
1.038 moles CO₂ * (44.01g / mol) =
45.7g of CO₂ is the maximum amount of carbon dioxide that could be produced.In chemical reactions, elements tend to combine with other elements to____ stability and ____ total energy
Answer:
In chemical reactions, elements tend to combine with other elements to INCREASE_ stability and DECREASE total energy.
Explanation:
The chemical compounds when joining are more stable in external media such as solvents or solutions already formed, although this union with another chemical compound removes total energy from the compound.
A force of 7 N acts on an object. The displacement is, say 8 m, in the direction of the force. Let us take it that the force acts on the object through the displacement. What is the work done in this case?
Answer:
56 J
Explanation:
Step 1: Given data
Force applied on the object (F): 7 NDisplacement of the object (d): 8 mStep 2: Calculate the work (w) done on the object
We can find the work done on the object using the following expression.
w = F × d × cosθ
where
θ is the angle between F and d
Since F and d occur in the same direction, θ = 0° and cosθ = 1. Then,
w = F × d × 1
w = F × d
w = 7 N × 8 m = 56 J
A sample of saturated clay was placed in a container and weighed. The weight was 6N. The clay in its container was placed in an oven for 24 hours at 105° C. The weight reduced to a constant value of 5N. The weight of the container is 1N. If G-2.7, determine the:
(a) water content;
(b) void ratio;
(c) bulk unit weight;
(d) dry unit weight;
(e) effective unit weight.
Answer is given below
Explanation:
given data
weight = 6N
temp = 105° C
weight reduced = 5N
solution
weight of container is 1N
SO W = (6-1) = 5
And Wd = 5 - 1 = 4
so
moisture content is
moisture content = [tex]\frac{W-Wd}{Wd} \times 100[/tex] .......1
moisture content = [tex]\frac{5-4}{4} \times 100[/tex]
moisture content = 25%
and
as we know density of soil soild = 2700 kg/m³
density of water = 1000 kg/m³
and sp gravity of soil = [tex]\frac{2700}{1000}[/tex] = 2.7
so
now we get here bulk unit weight
bulk unit wt = [tex]Yw \times [\frac{G+e}{1+e}][/tex] ..........2
bulk unit wt = [tex]9.01 \times [\frac{2.7 + 0.675}{1+0.675}][/tex]
bulk unit wt = 19.766 KN/m³
and
so dry unit wt will be
dry unit wt = [tex]\frac{Ysat}{1+w}[/tex] ..............3
dry unit wt = [tex]\frac{19.766}{1+0.25}[/tex]
dry unit wt = 15.813 kN/m³
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
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 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
Choose the catabolic reaction.
A. Breaking down a complex molecule
B. Synthesizing a complex molecule
C. CO2 and H2O combining to form carbonic acid.
Answer:
B. Synthesizing a complex molecule
Explanation:
Hello!
In this case, since catabolic reactions are related to the synthesis of complex biomolecules and metabolic reactions to the breaking down of complex molecules to obtain energy from (say start), we infer that the appropriate answer is:
B. Synthesizing a complex molecule
Because regardless C. also mentions the synthesis of a compound, carbonic acid is not a complex one in comparison to the biomolecules we produce during our cellular cycles.
Best regards!
us
If the mole fraction of NaCl in an
aqueous solution is 0.0927, what is
the weight/weight % (percent by
mass) of NaCl.
Molar Mass
Naci: 58.44 g/mol
H2O: 18.016 g/mol
Answer:
24.9%
Explanation:
According to this question, mole fraction of NaCl in an aqueous solution is 0.0927. This means that the mole percent of NaCl in the solution is:
0.0927 × 100 = 9.27%
Let's assume that the solution contains water (solvent) + NaCl (solute), hence, the mole fraction of water will be;
100% - 9.27% = 90.73%
THEREFORE, it can be said that, NaCl contains 0.0927moles while H2O contains 9.073moles
N.B: mole = mass/molar mass
Given the Molar Mass
NaCl: 58.44 g/mol
H2O: 18.016 g/mol
For NaCl;
0.0927 = mass/58.44
mass = 0.0927 × 58.44
5.42g
For H2O;
9.073 = mass/18.016
mass = 9.073 × 18.016
= 16.35g
Total mass of solution = 16.35g + 5.42g = 21.77g
Mass percent of NaCl = mass of NaCl/total mass × 100
% mass of NaCl = 5.42g/21.77g × 100
= 0.249 × 100
= 24.9%
Answer:
24.9
Explanation:
which of the following is the best thermal insulator?
1. Steel
2. Iron
3. Polystyrene
Answer:
3
Explanation:
Answer:
best guess is polystyrene
Explanation:
A student performs an experiment to determine the molar mass of magnesium oxide. The student repeats the experiment five times and collects the following data: 40.220gmol, 40.654gmol, 40.314 gmol, 40.165 gmol, and 40.554 gmol. If the accepted value for the molar mass is 40.304 gmol, what is the percent relative error for the average of this data?
Answer:
Percent relative error = 0.191%
Explanation:
Relative error is a measure of accuracy (How closeness is the measure to the accepted value) for a determined data. The formula is:
Percent relative error = |Experimental - Accepted| / Accepted * 100
Where experimental is the average of the data:
(40.220g/mol + 40.654g/mol + 40.314g/mol + 40.165g/mol + 40.554g/mol) / 5 =
40.381g/mol
Replacing using accepted value = 40.304g/mol:
|40.381g/mol - 40.304g/mol| / 40.304g/mol * 100
Percent relative error = 0.191%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%
7. Use the concepts of relative abundance and relative weight to explain why carbon has an atomic mass of 12.011 amu when there are three isotopes of carbon weighing 12 amu, 13 amu and 14 amu. Why is the atomic mass not 13?
The uncertainties of the delta measurements and the uncertainty of the atomic weight derivedfrom the best measurement of isotopic abundances constrain the number of significant figures in theatomic-weight values of the upper and lower bounds. For carbon, the fifth digit after the decimal pointis uncertain because of the uncertainty value of 0.000 027. Therefore, the number of significant digitsin the atomic-weight value is reduced to four figures after the decimal point. The Commission may rec-ommend additional conservatism and reduce the number of significant figures further. For the lowerbound of carbon, 12.009 635 is truncated to 12.0096. For an upper bound, the trailing digit is increasedto ensure the atomic-weight interval encompasses the atomic-weight values of all normal materials. Inthe case of carbon, the upper bound is adjusted from 12.011 532 to 12.0116 to express four digits afterthe decimal point. The lower and upper bounds are evaluated so that the number of significant digits ineach is identical. If a value ends with a zero, it may need to be included in the value to express therequired number of digits. The following are examples of lower and upper atomic-weight bounds foroxygen that could be published by the Commission in its various tables.
---------------------------
Extracted from" Atomic weights of the elements 2009 (IUPAC Technical Report)"
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°Cwhich 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 ✌
Last week at a tax free sale, Ms. Kuhn bought 4 shirts for $15.95 each and 2 new belts
that cost $8.95 each. If she paid with a $100 bill, how much change did she receive?
$18.30
$75.10
$2490
$24.90
Answer:
$18.30
Explanation:
The change is the amount left over after the selling price has been matched by the buyer.
Let us find the total cost of what of Ms. Kuhn bought;
For the shirt;
Cost = 4 shirts for $15.95 each = 4(15.95) = $63.8
2 new belts for $8.95 each = 2(8.95) = $17.9
Total cost = $63.8 + $17.9 = $81.7
The amount of change left = $100 - $81.7 = $18.3
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. What is the percent by mass of platinum?
Answer:
57.26 %
Explanation:
Step 1: Write the balanced equation
Pt + 2 HCl ⇒ PtCl₂ + H₂
Step 2: Calculate the mass of Pt in 1.778 g of PtCl₂
According to the law of conservation of the mass, all the mass of Pt in the reactants must be present in the products. Since PtCl₂ is the only product that contains Pt, the mass of Pt is 1.018 g
Step 3: Calculate the percent by mass of platinum in PtCl₂
We will use the following expression.
%Pt = mPt / mPtCl₂ × 100%
%Pt = 1.018 g / 1.778 g × 100% = 57.26 %
I need help with answer 1 and 2 ASAP please!!
Answer:
1. B 2.B
Explanation:
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.
first answer will get brainliest
Answer:
Incorrect
Explanation:
Mole ratios are derived from the coefficients in front of the number, N2O does not have a 2 in front of it, the real mole ratio would be 4/1
Answer:
Correct
Explanation:
I had the same problem and I put correct, and it was correct.
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!
Please help me on this
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 :)
ANSWER 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
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.why do we need nucleic acid in our cells?
Explanation:
Nucleic acids are the most important macromolecules for the continuity of life. They carry the genetic blueprint of a cell and carry instructions for the functioning of the cell.
Which of the following is the set of conditions under which a material becomes a supercritical fluid?
A. real gas point
B. critical point
C. extreme point
D. triple point
(multiple choice)
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
If you rewite the following word equation as a balanced chemical equation, what will the coefficient and symbol for iodine be?
bromine + potassium iodide → potassium bromide + iodine
A 2I
B I
C 2I
D I2
E 2I2
The coefficient and symbol for iodine be I₂.
What is the coefficient in a chemical equation?Coefficients are the numbers used to balance chemical equations and are placed in front of a chemical symbol or formula. It tells us about how many atoms or molecules of substance or compound are involved in the reaction.As in mathematics, coefficient is the number used in front of a variable similarly in chemistry, coefficient is a number used in chemical equation, just as a prefix of chemical formula to define the number of molecules reacting and producing in a reaction. We add coefficients to balance the chemical equations so as to assure that law of conservation of mass is being followed.bromine + potassium iodide → potassium bromide + iodine
The balanced chemical equations:
Br₂ + 2KI → 2KBr + I₂
2KBr means 2 molecules of potassium iodide.
From the above balanced equation, we know that the coefficient of bromine = 2, iodine = 2, potassium iodide = 2and potassium bromide = 2.
Hence, option D is the correct answer.
To learn more about coefficient in chemical equation here
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