34.某化學(xué)興趣小組的同學(xué)為測(cè)定Cu和CuO混合樣品中CuO的含量,甲、乙、丙、丁四位同學(xué)均先稱取20g樣品于燒杯中,在分別加入20g、40g、60g、80g溶質(zhì)質(zhì)量分?jǐn)?shù)相同的稀硫酸.充分反應(yīng)后,均有固體剩余.經(jīng)過(guò)濾、干燥后稱量,剩余固體質(zhì)量如下圖所示.回答下列問(wèn)題:
(1)20g樣品中含單質(zhì)Cu
g;
(2)求樣品中CuO的質(zhì)量分?jǐn)?shù).