A mixture of sodium hydrogencarbonate and sodium chloride is heated. The equation for the reaction that takes place when sodium hydrogencarbonate is heated is shown. 2NaHCO3(s) → Na2CO3(s) + CO2(g) + H2O(g) Sodium chloride is unchanged on heating. When 6.0 g of the mixture is heated, the loss in mass is 1.5g. What is the percentage by mass of sodium hydrogencarbonate in the mixture? [relative molecular mass, Mr: NaHCO3, 84; Na2CO3, 106; CO2, 44; H2O, 18]

The equation for the burning of hydrogen in oxygen is shown. 2H2(g) + O2(g) → 2H2O(g) What does this equation indicate?

For which molecules are the empirical and molecular formulae the same? 1. methanoic acid, HCO2H 2. ethanoic acid, CH3…

A 10 cm³ sample of a gaseous hydrocarbon is completely burnt in oxygen. The total volume of the products is 70 cm³. A…

The addition of dilute acid to a solution containing the anion Q and the subsequent use of limewater can be used to i…

Four substances have the following electrical properties. What are these four substances?

The proton number of element X is 6. The proton number of element Y is 9. What is the formula of a compound of these …