Calcium and Magnesium carbonates occur together in the mineral dolomite. Suppose you heat a sample of the mineral to obtain the oxides, CaO and MgO, and then treat the oxide sample with hydrochloric acid. If 7.695 g of the oxide sample requires 125 mL of 2.55 M HCl,CaO + 2 HCl gt;gt; CaCl2 + H2OMgO + 2 HCl gt;gt; MgCl2 + H2OWhat in the weight percentage of each oxide (CaO and MgO) in the sample?
roughly 32% depending on the 7-day weather forecast
moles HCl 0.125 L x 2.55 0.319 the ratio between MgO and HCl is 1 : 2 and the ratio between CaO and HCl is 1 : 2 moles MgO + moles CaO 0.319/2 0.159 let x mass CaO let y mass MgO x + y 7.695 x / 56 +y / 40.3 0.159 x 7.695-y (7.695 - y) 40.3 + 56 y 358.8 310.1 - 40.3 y + 56 y 358.8 15.7 y 48.7 y 3.10 g % MgO 3.10 x 100 / 7.69540.3 % CaO 59.7
