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4 years ago

"solid potassium iodide decomposes into iodine gas and solid potassium. Write a a balanced chemical equation for this reaction"

1 answer:

wel4 years ago

3 0

$KI (s) ----\ \textgreater \ K(s) + I_2 (g)$

Now, balance the equation:

$2KI (s) ----\ \textgreater \ 2K(s) + I_2 (g)$

$I_2$ in gaseous state exist as a diatomic molecule.

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The kind of sub-atomic particle that does not make up the nucleus of an atom is:

Andrew [12]

$\sf \: QuEsTiOn :$

The kind of sub-atomic particle that does not make up the nucleus of an atom is:

$\sf \: AnSwEr :$

B) Neutron

Hope It's Helps^^

7 0

3 years ago

Small quantites of hydrogen gas can be prepared in the laboratory by the addition of aqueous hydrochloric acid to metallic zinc.

ira [324]

<u>Answer:</u> The mass or zinc reacted is 0.624 grams.

<u>Explanation:</u>

We are given:

Total pressure = 1.032 atm

Vapor pressure of water = 32 torr = 0.042 atm (Conversion factor: 1 atm = 760 torr)

To calculate partial pressure of hydrogen gas, we use the equation:

$p_{H_2}=p_T-p_{H_2O}\\\\p_{H_2}=1.032-0.042=0.99atm$

To calculate the number of moles of hydrogen gas, we use the equation given by ideal gas follows:

$PV=nRT$

where,

P = pressure of hydrogen gas = 0.99 atm

V = Volume of hydrogen gas = 240. mL = 0.240 L (Conversion factor: 1 L = 1000 mL)

T = Temperature of hydrogen gas = $30^oC=[30+273]K=303K$

R = Gas constant = $0.0821\text{ L. atm }mol^{-1}K^{-1}$

n = number of moles of hydrogen gas = ?

Putting values in above equation, we get:

$0.99atm\times 0.240L=n\times 0.0821\text{ L atm }mol^{-1}K^{-1}\times 303K\\n=\frac{0.99\times 0.240}{0.0821\times 303}=9.55\times 10^{-3}mol$

The chemical equation for the reaction of zinc and hydrochloric acid follows:

$Zn+2HCl\rightarrow ZnCl_2+H_2$

By Stoichiometry of the reaction:

1 mole of hydrogen gas is produced from 1 mole of zinc metal

So, $9.55\times 10^{-3}mol$ of hydrogen gas is produced from = $\frac{1}{1}\times 9.55\times 10^{-3}=9.55\times 10^{-3}mol$ of zinc metal

To calculate the mass of zinc metal, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Molar mass of zinc = 65.38 g/mol

Moles of zinc = $9.55\times 10^{-3}$ moles

Putting values in above equation, we get:

$9.55\times 10^{-3}mol=\frac{\text{Mass of zinc}}{65.38g/mol}\\\\\text{Mass of zinc}=(9.55\times 10^{-3}mol\times 65.38g/mol)=0.624g$

Hence, the mass or zinc reacted is 0.624 grams.

4 0

4 years ago

For which process is ΔS negative? Group of answer choices A. grinding a large crystal of KCl to powder B. raising the temperatur

ludmilkaskok [199]

Answer:

Explanation:

The entropy (S) is the measure of the randomness of a system, and ΔS = Sfinal - Sinitial. As higher is the disorder of the system, as higher is the entropy.

A. When KCl is fractionated in power, there'll be more portions of it, so, the disorder must be higher, then ΔS is positive.

B. As higher is the temperature, higher is the kinetic energy of the system, and because of that, the disorder is also higher, so ΔS is positive.

C. The decrease in the volume (compression) decreases the distance between the molecules, so the system will be more organized, then ΔS is negative.

D. The volume before the mixing will be higher, and the ethanol will dissociate, so it will be more particles, the disorder will increase, and ΔS is positive.

E. Sgas > Sliquid > Ssolid because of the disorder of the molecules, then ΔS is positive.

5 0

4 years ago

For question 9 I need help push or pull

adelina 88 [10]

Answer:

a push

please thank and brainlest!

Explanation:

5 0

3 years ago

Hahsusiaianbaisisii jsusis

photoshop1234 [79]

Answer:

yes i understand

Explanation:

i feel you

7 0

3 years ago

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