Answer:
The mass of 10 cm³of a 0.4 g/dm³ solution of sodium carbonate is 0.004 grams
Explanation:
The question is with regards to density calculations
The density of the given sodium carbonate solution, ρ = 0.4 g/dm³
The volume of the given solution of sodium carbonate, V = 10 cm³ = 0.01 dm³


Therefore, we have;

The mass, "m", of the sodium carbonate in = ρ×V = 0.4 g/dm³ × 0.01 dm³ = 0.004 g
The mass of 10 cm³ (10 cm³ = 0.01 dm³) of a 0.4 g/dm³ solution of sodium carbonate, m = 0.004 g.
The water and heathfshiccu
Answer:
2 moles of Substance B
Explanation:
Because 1 mole of any substance contains 6.02× 10²³ particles either atoms, molecules, ions or even electron(Avogardo Constant)
Therefore 12.04 × 10²³/ 6.02× 10²³ = 2 mole of Substance B