Question

3. Solid potassium nitrate is decomposed by heating to give potassium nitrite and oxygen gas. If 1.00 g of potassium nitrate is heated, what is the milliliter volume of oxygen gas at STP? 42 KNO2(s) 02(8) 2 KNO,(6) 4. Potassium metal reacts with water to give potassium hydroxide and hydrogen gas. If 50.0 mL of hydrogen gas is produced at STP, what is the mass of potassium that reacted? На) 2 КОН аg) 2 K(s) 2 H20() + 5. (optional) The Solvay process is an industrial method for preparing baking soda. In the process, CO2, NH3, H20, and NaCl react to produce NaHCÓ3. If 10.0 L of carbon dioxide gas at STP and 50.0 g of sodium chloride react with excess ammonia and water, what is the limiting reactant and the mass of baking soda produced? NAHCO3(s)NH4CI (aq) CO2(g) NH(g) + H20() +NaCl(s)
what do I do?

Answer 1

3. Ans :-

As,

Number of moles = Given mass in g / Gram molar mass

So,

Number of moles of KNO₃ = 1.00 g / 101.1032 g/mol

= 0.00990 mol

Given chemical reaction is :

2 KNO₃ (s) + Heat -----------------> 2 KNO₂ (s) + O₂ (g)

In this balance chemical equation 2 moles of KNO₃ solid gives 1 mole of O₂ gas.

That is :

2 mole of KNO₃ gives = 1 mole of O₂ gas

So,

0.00990 moles of KNO₃ gives = 0.00990 mol / 2 = 0.00495 mol of O₂ gas

Also,

Volume of O₂ gas at STP = Moles x Molar volume in ml

So,

Volume of O₂ gas at STP = 0.00495 mol x 22400 ml = 110.88 ml

Hence, Volume of O2 gas formed = 110.88 ml