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Softa [21]
3 years ago
11

I really need someone to explain how to find the average atomic mass.... the gizmos was really confusing because they also had w

eighted mass.

Chemistry
1 answer:
evablogger [386]3 years ago
5 0

Answer:

Option C. 52.057

Explanation:

The following data were obtained from the question:

Isotope >> Mass number > Percentage

A (Cr-50) > 50 >>>>>>>>>> 4.3

B (Cr-52) > 52 >>>>>>>>>> 83.8

C (Cr-53) > 53 >>>>>>>>>> 9.5

D (Cr-54) > 54 >>>>>>>>>> 2.4

Average atomic mass =?

The average atomic mass of chromium, Cr can be obtained as follow:

Average atomic mass = [(Mass of A × A%) /100] + [(Mass of B × B%) /100] + [(Mass of C × C%) /100] + [(Mass of D × D%) /100]

Atomic mass of Cr = [50×4.3)/100] + [52×83.8)/100] + [53×9.5)/100] + [54×2.4)/100]

= 2.15 + 43.576 + 5.035 + 1.296

Atomic mass of Cr = 52.057

Therefore, the atomic mass of chromium, Cr is 52.057

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Ammonia will decompose into nitrogen and hydrogen at high temperature. An industrial chemist studying this reaction fills a 500.
yaroslaw [1]

Answer:

12. is the pressure equilibrium constant for the decomposition of ammonia at the final temperature of the mixture.

Explanation:

2NH_3(g)\rightleftharpoons N_2(g)+3H_2(g)

initially

3.0 atm      0              0

At equilibrium

(3.0-2p)     p               3p

Equilibrium partial pressure of nitrogen gas = p = 0.90 atm

The expression of a pressure equilibrium constant will be given by :

K_p=\frac{p_{N_2}\times (p_{H_2})^3}{(p_{NH_3})^2}

K_p=\frac{p\times (3p)^3}{(3.0-2p)^2}

=\frac{0.90 atm\times (3\times 0.90 atm)^3}{(3.0-2\times 0.90 atm)^2}

K_p=12.30\approx 12.

12. is the pressure equilibrium constant for the decomposition of ammonia at the final temperature of the mixture.

3 0
3 years ago
Determine which of the following statements is true:
alukav5142 [94]

Answer:

A. When an anhydrous salt becomes hydrated, it can change color.

Explanation:

The cobalt (II) chloride (CoCl₂) have a blue color in the anhydrous form while after hydration, most commonly it will form the hexahydrate, it will change its color to violet.

B. not really, if we take the cobalt (II) chloride in the anhydrous form the bond between cobalt and the chloride it is ionic.

C. nope, the mass is changed depending on the lost water mass

D. no, the mass will increase and sometimes as in the case of cobalt (II) chloride the color will change, so you have changes of the physical properties of the substance.

3 0
3 years ago
CAN SOMEONE ANSWER ME!! 5-6
docker41 [41]

Answer:

As the axial tilt increases, then the seasonal contrast increases so that winters are colder and summers are warmer in both hemispheres. The northern hemisphere is tipped away from the Sun, producing short days and a low sun angle. What kind of effect does the earth's tilt and subsequent seasons have on our length of daylight (defined as sunrise to sunset). Over the equator, the answer is not much.

7 0
2 years ago
Consider the malate dehydrogenase reaction from the citric acid cycle. Given the listed concentrations, calculate the free energ
Ahat [919]

<u>Answer:</u> The Gibbs free energy of the reaction is 21.32 kJ/mol

<u>Explanation:</u>

The chemical equation follows:

\text{Malate }+NAD^+\rightleftharpoons \text{Oxaloacetate }+NADH

The equation used to Gibbs free energy of the reaction follows:

\Delta G=\Delta G^o+RT\ln K_{eq}

where,

\Delta G = free energy of the reaction

\Delta G^o = standard Gibbs free energy = 29.7 kJ/mol = 29700 J/mol  (Conversion factor: 1 kJ = 1000 J)

R = Gas constant = 8.314J/K mol

T = Temperature = 37^oC=[273+37]K=310K

K_{eq} = Ratio of concentration of products and reactants = \frac{\text{[Oxaloacetate]}[NADH]}{\text{[Malate]}[NAD^+]}

\text{[Oxaloacetate]}=0.130mM

[NADH]=2.0\times 10^2mM

\text{[Malate]}=1.37mM

[NAD^+]=490mM

Putting values in above expression, we get:

\Delta G=29700J/mol+(8.314J/K.mol\times 310K\times \ln (\frac{0.130\times 2.0\times 10^2}{1.37\times 490}))\\\\\Delta G=21320.7J/mol=21.32kJ/mol

Hence, the Gibbs free energy of the reaction is 21.32 kJ/mol

4 0
3 years ago
Pedro is baking a cake for his experiment on chemical changes. He knows a chemical change will occur when he puts the cake mixtu
tester [92]

Answer:

A. The chemical changes occurred because the chemicals changed.

Explanation:

When baking a cake several chemical reactions occur that change the chemical composition of the ingredients used in baking. An ingredient like baking powder releases carbon dioxide when it undergoes a temperature change in the oven. A chemical change is supposed to change the form of a substance.

An endothermic reaction also occurs when the ingredients absorb heat energy to produce several changes. The firmness of the cake occurs because of the heat absorbed by the proteinous content of the egg.

7 0
3 years ago
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