1.
V = 200 mL (volume)
c = 3 M = 3 mol/L (concentration)
First we convert mL to L:
200 mL = 0.2 L
Then we calculate the moles using the formula: n = V × c = 0.2 L × 3 mol = 0.6 mol
Finally, we just use the molar mass of CaF2 to calculate the actual mass:
molar mass = 78 g/mol
The formula is: m = n × mm (mass = moles × molar mass)
m = 0.6 mol × 78 g/mol = 46.8 g
2.
For this question the steps are exactly like the first question.
V = 50mL = 0.05 L
c = 12 M = 12 mol/L
n = V × c = 0.05 L × 12 mol/L = 0.6 mol
molar mass (HCl) = 36.5 g/mol
m = n × mm = 0.6 mol × 36.5 g/mol = 21.9 g.
3.
The steps for this question are the opposite way.
m(K2CO3) = 250 g
molar mass = 138 g/mol
n = m ÷ mm = 1.81 mol
c = 2 mol/L
V = n ÷ c = 1.81 mol ÷ 2 mol/L = 0.905 L = 905 mL
Answer:
The answer is b. The number of collisions of gas particles increases
Add gelatin and let it boil, then put it in the freezer for 30 minuets
Correct Answer: Mass of ore that contains 200 g of Ti is
617.28 g.
Reason:
Given: Ore contains 32.4% Ti by mass.
It implies that, 100 g of ore ≡ 32.4 g of Ti
Therefore, x g of ore ≡ 200 g of Ti
Thus, x =

Hence, mass of ore that contains 200 g of Ti is
617.28 g.
Answer:
292 mL
Step-by-step explanation:
The pressure is constant.
The only variables are volume and temperature, so we can use <em>Charles’ Law.</em>
V₁/T₁ = V₂/T₂ Multiply each side by T₂
V₂ = V₁ × T₂/T₁
V₁ = 250 mL; T₁ = 300 K
V₂ = ?; T₂ = 350 K
V₂ = 250 × 350/300
V₂ = 292 mL