A mixture of CaCO₃ and CaO has a mass of 2.5000 g. After heating, the mass of the sample is reduced to 2.016 g due to the decomposition of CaCO₃ into CaO and CO₂. What is the mass percent of CaCO₃ in the original mixture?

The volume of HCl gas required to react with excess Mg metal to produce 6.82 L of hydrogen gas at 2.19 atm and 35°C is ________ L. 2 HCl (g) + Mg (s) → MgCl2 (s) + H2 (g)

A 0.846-g sample containing barium ions is completely dissolved in water and treated with excess Na2SO4. 0.746 g of BaSO4 precipitates. What is the mass percent of barium in the sample?

A 10.0 mL solution of 0.121 M H₂SO₄ is neutralized by 17.1 mL of KOH solution. What is the molarity of the KOH solution?

A mixture of 1.88 moles of hydrogen and 0.92 moles of oxygen are used in the reaction. According to the balanced chemical equation 2H₂ + O₂ → 2H₂O, how many moles of water would be produced if you used up all the hydrogen?

A mixture of NaCl and NaBr has a mass of 2.01 g and is found to contain 0.77 g of Na. What is the mass of NaBr in the mixture?

A sample of acetic acid is composed of 2.05 g of carbon and 2.73 g of oxygen. Calculate the mass of carbon in another sample of acetic acid that is composed of 3.27 g of oxygen.

A student dissolved 4.00 g of Co(NO3)2 in enough water to make 100.0 mL of stock solution. He took 4.00 mL of the stock solution and then diluted it with water to give 275.0 mL of a final solution. How many grams of NO3- ion are there in the final solution?

According to the balanced equation 3 NO2(g) + H2O(l) ⟶ 2 HNO3(aq) + NO(g), how many moles of NO are formed from 8.44 moles of NO2 if there is plenty of water present?