Answer:
P' = 41.4 mmHg → Vapor pressure of solution
Explanation:
ΔP = P° . Xm
ΔP = Vapor pressure of pure solvent (P°) - Vapor pressure of solution (P')
Xm = Mole fraction for solute (Moles of solvent /Total moles)
Firstly we determine the mole fraction of solute.
Moles of solute → Mass . 1 mol / molar mass
20.2 g . 1 mol / 342 g = 0.0590 mol
Moles of solvent → Mass . 1mol / molar mass
60.5 g . 1 mol/ 18 g = 3.36 mol
Total moles = 3.36 mol + 0.0590 mol = 3.419 moles
Xm = 0.0590 mol / 3.419 moles → 0.0172
Let's replace the data in the formula
42.2 mmHg - P' = 42.2 mmHg . 0.0172
P' = - (42.2 mmHg . 0.0172 - 42.2 mmHg)
P' = 41.4 mmHg
Answer:
a ) 1876.14 grams CaBr2
b ) 19.78 grams N2
sorry..i only have time to do the first two :)
Explanation:
<h3>
Answer:</h3>
1.001
120.0
<h3>
Explanation:</h3>
Significant figures are used in science to determine the precision of a number. Depending on the decimal point, sig figs are counted in different ways.
Decimal Points
When counting sig figs, you always start at the first non-zero number. However, sometimes you start from the left, other times the right.
- If the decimal point is present, start counting sig figs from the left.
- If the decimal point is absent, start counting sig figs from the right.
Remember to start counting at the first non-zero number.
For people in the Americas, there is a trick to remembering this.
- If this decimal is Present, start from the Pacific. If it is Absent, start from the Atlantic.
This works because the Pacific ocean is to the left of the Americas, and the Atlantic is to the right.
4 Significant Figures
The number 1.001, has 4 significant figures. Since there is a decimal point, we start counting from the left. The first digit is not zero, so we count all four places as significant.
The number 120.0 also has 4 sig figs. Like the number above, we start counting from the left because of the decimal. The first digit on the left is not zero, so we once again count all 4 digits as significant.
