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3 years ago

Solid potassium chlorate decomposes upon heating to form

Chemistry

1 answer:

olga55 [171]3 years ago

3 0

Answer:

32.6%

Explanation:

Equation of reaction

2KClO₃ (s) → 2KCl (s) + 3O₂ (g)

Molar mass of 2KClO₃ = 245.2 g/mol ( 122.6 × 2)

Molar volume of Oxygen at s.t.p = 22.4L / mol

since the gas was collected over water,

total pressure = pressure of water vapor + pressure of oxygen gas

0.976 = 0.04184211 atm + pressure of oxygen gas at 30°C

pressure of oxygen = 0.976 - 0.04184211 = 0.9341579 atm = P1

P2 = 1 atm, V1 = 789ml, V2 = unknown, T1 = 303K, T2 = 273k at s.t.p

Using ideal gas equation

$\frac{P1V1}{T1}$ = $\frac{P2V2}{T2}$

V2 = $\frac{P1V1T2}{T1P2}$

V2 = 664.1052 ml

245.2 yielded 67.2 molar volume of oxygen

0.66411 will yield = $\frac{245.2 * 0.66411}{67.2}$ = 2.4232 g

percentage of potassium chlorate in the original mixture = $\frac{2.4232 * 100}{7.44}$ = 32.6%

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Consider the reaction Mg₂Si(s) + 4 H₂O(ℓ) → 2 Mg(OH)₂(aq) + SiH₄(g). How many grams of silane gas (SiH₄) are formed if 25.0 g of

Neko [114]

Answer:

10.60 grams of silane gas are formed.

Explanation:

From the reaction:

Mg₂Si(s) + 4H₂O(l) → 2Mg(OH)₂(aq) + SiH₄(g)

We know that the limiting reactant is Mg₂Si, so to find the mass of SiH₄ formed we need to calculate the number of moles of Mg₂Si:

$\eta_{Mg_{2}Si} = \frac{m_{Mg_{2}Si}}{M_{Mg_{2}Si}}$

Where:

m: is the mass of Mg₂Si = 25.0 g

M: is the molar mass of Mg₂Si = 76.69 g/mol

$\eta_{Mg_{2}Si} = \frac{m_{Mg_{2}Si}}{M_{Mg_{2}Si}} = \frac{25.0 g}{76.69 g/mol} = 0.33 moles$

Now, the stoichiometric relation between Mg₂Si and SiH₄ is 1:1 so:

$\eta_{Mg_{2}Si} = \eta_{SiH_{4}} = 0.33 moles$

Finally, the mass of SiH₄ is:

$m_{SiH_{4}} = \eta_{SiH_{4}}*M_{SiH_{4}} = 0.33 moles*32.12 g/mol = 10.60 g$

Therefore, 10.60 grams of silane gas are formed.

I hope it helps you!

3 0

3 years ago

Why do solids not diffuse

Ulleksa [173]

Answer:

This is because of diffusion , the movement of particles from an area of high concentration to an area of low concentration. ... This means that diffusion does not happen in solids – the particles in a solid can only vibrate and cannot move from place to place.

8 0

2 years ago

Read 2 more answers

Atoms of element X weigh 32 times more than atoms of element Y. A compound has the formula: XY2 The ratio of the mass of X to th

tamaranim1 [39]

Answer:

16:1

Explanation:

Atoms of element X weigh 32 times more than atoms of element Y. We can write this in a symbolic way.

mX = 32 mY [1]

where,

mX and mY are the masses of X and Y, respectively

A compound has the formula: XY₂, that is, in 1 molecule of XY₂ there is 1 atom of X and 2 atoms of Y. The ratio of the mass of X to the mass of Y in this compound equals:

mX/2 mY [2]

If we substitute [1] in [2], we get:

mX/2 mY = 32 mY/2 mY = 16 = 16:1

4 0

3 years ago

What is the % yield when 12g of Mg react with HCl to produce 0.2g of H2?

goblinko [34]

Answer:

The yield is 20 %.

Explanation:

Mg + 2 HCl → MgCl2 + H2

(12 g Mg) / (24.30506 g Mg/mol) x (1 mol H2 / 1 mol Mg) x (2.015894 g H2/mol) = 0.9953 g H2.

(0.2 g) / (0.9953 g) = 0.20 = 20% yield

5 0

3 years ago

Identify the correct net ionic equation for the reaction that occurs when solutions of Pb(NO3)2 and NH4Cl are mixed.

Pie

Answer:

Pb2+(aq) + 2Cl–(aq) ----> PbCl2(s)

Explanation:

The net ionic equation shows the main reaction that takes place in a system. Hence, a net ionic equation focusses only on those species that actually participate in the reaction.

For the reaction between Pb(NO3)2 and NH4Cl , the net ionic equation is;

Pb^+(aq) + 2Cl^-(aq) ---> PbCl2(s)

7 0

3 years ago