C. they expand to fill all the space
Answer is: mass of sodium nitrate is 21,25 g.
m(H₂O) = 500 g · 1 kg/1000 g = 0,5 kg.
b(solution) = 0,500 m = 0,500 mol/kg.
m(NaNO₃) = ?
b(solution) = n(NaNO₃) ÷ m(H₂O).
n(NaNO₃) = 0,500 mol/kg · 0,5 kg.
n(NaNO₃) = 0,25 mol.
m(NaNO₃) = n(NaNO₃) · M(NaNO₃).
m(NaNO₃) = 0,25 mol · 85 g/mol.
m(NaNO₃) = 21,25 g.
Answer:
The same number of proteins in their nucleus.
For which of the following activities might you want to hire a chemist?
Answer: D. testing a rock sample for gold content
Which of the following procedures involves a physical change in one of the substances?
Answer: C. separating a salt solution by evaporating the water
I think it could be C maybeee though
