Physical changes can be reversed and chemical changes can’t be reversed. A physical property is a characteristic which can be identified without changing the substance but to identify a chemical property, you do have to change the substance.
Answer:
Explanation:
<u>1) Data:</u>
a) V₁ = 38.2 liter
b) P₁ = 91 psi
c) V₂ = 77.4 liter
d) P₂ = ?
<u>2) Formula:</u>
According to Boyle's law, at constant temperature, the pressure and volume of a fixed amount of gas are inversely related:
- PV = constant ⇒P₁V₁ = P₂V₂
<u>3) Solution:</u>
- Solve for the unknown: P₂ = P₁V₁ /v₂
- Substitute the values: V₂ = 91 psi × 38.2 liter / 77.4 liter = 44.9 9si ≈ 45 psi.
Molality is defined as the number of moles of solute in 1 kg of solvent.
molality of solution to be prepared is 0.50 molal
this means that in 1000 g of water there should be 0.50 mol of NaCl
if 1000 g of water should contain - 0.50 mol
then 750.0 g of water requires - 0.50 mol/kg x 0.750 kg = 0.375 mol
mass of NaCl in 0.375 mol - 58.5 g/mol x 0.375 mol = 21.9 g
therefore a mass of 21.9 g of NaCl is required
Answer:
I think it's D
Explanation:
I'm so sorry if that's wrong, hope it helps!
C because neither the water or salt have changed their molecular structure. H2O is still H2O and NaCl is still NaCl.
