A copper road coated with copper (II) oxide has a mass of 38.72 g. The rod is heated and made to react with 5.67 L of Hydrogen gas, whose density at the conditions of the experiment is 0.0519 g/L. What is the mass of the copper after all the hydrogen is consumed? (Assume that CuO is converted only to Cu.)

During a laboratory experiment, a student initiated a reaction with 19.5 g of NaBH4 and excess BF3. When the reaction was complete, the student had collected 7.00 g of B2H6 gas. From this data, calculate the percent yield of B2H6.

Copper(II) sulfate forms several hydrates with the general formula CuSO4·xH2O, where x is an integer. If the hydrate is heated, the water can be driven off, leaving pure CuSO4 behind. Suppose a sample of a certain hydrate is heated until all the water is removed, and it's found that the mass of the sample decreases by 31.%. Which hydrate is it? That is, what is x?

Consider the copper thermite reaction, a reaction between two solids that can be initiated with strong heating: 3 CuO(s) + 2 Al(s) → 3 Cu(s) + Al2O3(s) 25.0 g of copper(II) oxide are combined with 25.0 g of Al , and the mixture is heated strongly to react. molar masses (g/mol):  CuO - 79.55    Al - 26.98    Cu - 63.55 What is the chemical formula or elemental symbol for the limiting reactant?   What is the chemical formula or elemental symbol for the excess reactant?

A sample of a substance (containing only C, H, and N) is burned in oxygen.3.375 g of CO2, 4.935×10-1 g of H2O and 6.575×10-1 g of NO are the sole products of combustion.What is the empirical formula of the compound?   What was the mass of the initial sample burned?

A chemist invents a new combustion analysis instrument that uses less O2(g) which saves money on each analysis. The improvement is that instead of CO2(g) being formed and trapped, CO(g) is formed and trapped. H2O (g) is also formed and trapped when substances that contain hydrogen are analyzed.(a) The chemist places 2.184 g of an unknown compound of carbon and hydrogen in the new analyzer. 4.627 g of CO (g) and 1.795 g of H2O (g) are produced. Find the empirical formula for the compound.(Molar masses (g/mol): CO = 28.0104, H2O = 18.015) (b) Despite the best efforts of the chemist, the molar mass of the compound cannot be determined (using this method). Clearly explain why this prevents the determination of the molecular formula

What is the mole ratio of calcium carbonate to carbon dioxide in the reaction between hydrochloric acid and calcium carbonate? 2HCl + CaCO3 --> CaCl2 + CO2 + H2O

Calculate the volume of 5.0 M NaH to prepare 250 mL of 0.10 M NaOH

A website promoting the use of alternative energy vehicles and hybrid technologies claims that "A typical automobile in the USA uses about 500 gal of gasoline every year, producing about 5 tons of carbon dioxide." To determine the truth of this statement, calculate how many tons of carbon dioxide are produced when 500.0 gal of gasoline are combusted. Assume that the primary ingredient in gasoline is octane, C H₁ (1), which has a density of 0.703 g · mL-¹. 18 CO₂ produced: tons

An impure sample of table salt (NaCl) that was dissolved in water and treated with silver nitrate to form silver chloride. If the initial sample had a mass of 1.741 g and the final mass of the AgCl was found to be 4.084 g, what is the mass percent of NaCl in the impure sample?