1. <span>Substances in a </span>mixture<span> can be separated using different </span>methods, for example <span>distillation (separation of two liquids).
2. </span>Mass<span> is the amount of matter an object contains.
</span>Volume is t<span>he amount of space occupied by a three-dimensional object.
3. d(wallet) = 15g</span>÷5cm³ = 3g/cm³.
4. Weight of an astronaut also increases. W=m·g.
Answer : The correct option is, 0.21 moles
Solution : Given,
Molarity of the solution = 0.85 M = 0.85 mole/L
Volume of solution = 250 ml = 0.25 L 
Molarity : It is defined as the number of moles of solute present in one liter of the solution.
Formula used :

Now put all the given values in this formula, we get the moles of solute of the solution.


Therefore, the moles of solute is, 0.21 moles
A saturated solution is a solution that contains a certain amount of solute that is enough to be dissolved in the solvent. Anything above that amount will not dissolve some of the solute in the solvent. When a saturated solution is cooled, the solubility of the solute lowers making the solution supersaturated.
Answer:
Rate ≅ 1.01 M/s (3 sig. figs.)
Explanation:
Given A(g) + B(g) => AB(g)
Rate = k[A(g)][B(g)]²
at Rate (1) = 0.239M/s = k[2.00M][2.00M]² => k = (0.239M/s) / (2.00M)(2.00M)²
k = 0.29875 M⁻²·s⁻¹
Rate (2) = k[A(g)][B(g)]² = (0.29875M⁻²·s⁻¹)(4.81M)(2.65M)² = 1.009124472 M/s (calc. ans.) ≅ 1.01 M/s (3 sig. figs.)