Question

calcule a Massa de:
a) 0,5 mol CaCo3
b) 1,5 mol H2O
c) 2,0 mol HNO3
d) 0,2 mol H3PO4

Answer 1

a) 
Massa molar do CaCO3 = 40 + 12 + 16 x 3 = 100 g/mol

1 mol ---------- 100 g
0,5 mol -------- x g

x = 0,5 . 100

x = 50 g
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b)
Massa molar H2O = 1 x 2 + 16 = 18 g/mol

1 mol ----------------- 18 g
1,5 mol --------------- y g

y = 1,5 . 18

y = 27 g
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c)
Massa molar HNO3 = 1 + 14 + 16 x 3 = 63 g/mol

1 mol ---------------- 63 g
2,0 mol ------------- z g

z = 2,0 . 63

z = 126 g
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d)

Massa molar do H3PO4 = 1 x 3 + 31 + 16 x 4 = 98 g/mol

1 mol ---------------------- 98 g
0,2 mol-------------------- w g

w = 0,2 . 98

w = 19,6 g
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espero ter ajudado!