Answer:
a) 210 mL of 95% ethanol
b) 75 mL of water
Explanation:
a) We can use the dilution equation to solve this problem. C₁ and V₁ are the concentration and volume of the stock solution, respectively, while C₂ and V₂ are the concentration and volume of the diluted solution.
C₁V₁ = C₂V₂
We want to find V₁, the volume of ethanol stock we need to dilute to prepare the final solution:
V₁ = (C₂V₂) / C₁
The concentrations are represented in percentages. We substitute in the known values to calculate V₁. The units cancel to leave us with units of mL.
V₁ = (C₂V₂) / C₁ = (70%)(285mL) / (95%) = 210 mL
b) The final solution volume is 285 mL and we have added 210 mL of ethanol, so the remaining volume is from the water that we add:
(285 mL - 210 mL) = 75 mL
I may be able to depending on what it is about.
Can you give me the info?
Answer:
The empirical formula is PCl3
Explanation:
Mass of P is 30.97 g, thus 1.523 g of P equivalent to 0.05 moles of P
Mass of Cl is 35.45 g, thus 5.228 g of Cl equivalent to 0.15 moles of Cl
Therefore moles of P : moles of Cl = 0.05:0.15 = 1:3
Therefore the empirical formula, PCl3
