Answer:
340 grams Ca₃P₂ (2 sig. figs.)
Step-by-step explanation:
3Ca + 2P => Ca₃P₂
5.6 mole + excess => ? grams
Convert the 'known' to a coefficient of 1 by dividing all coefficients by 3.
=> Ca + 2/3P => 1/3Ca₃P₂
From the above, 1 mole of Ca => 1/3 mole Ca₃P₂
∴ 5.6 mole Ca in an excess of P => 1/3(5.6 mole) Ca₃P₂
=> 1.8666 mol Ca₃P₂ (calculator answer) ≅ 1.9 mol Ca₃P₂
=> 1.9 mole x 182 g Ca₃P₂/mol Ca₃P₂ = 339.73333 grams Ca₃P₂
≅ 340 grams Ca₃P₂ (2 sig. figs.)