Question

how many grams of k2cr207are therein 8.90×1024 molecules of k2cr207

Answer 1

1 mole of matter contains 6.022 × 10²³ units of that substance.

n = m / M

M (K₂Cr₂O₇) = 294.2 g/mol

n (K₂Cr₂O₇) = 8.90×10²⁴ / 6.022 × 10²³ = 14.8 mol

m (K₂Cr₂O₇) = n x M = 14.8 x 294.2 = 4348 g