Answer: Increases.
Explanation: As the temperature of a liquid or solid increases its vapor pressure also increases. Conversely, vapor pressure decreases as the temperature decreases.
Answer: Heating a crucible to remove water from a hydrate.
Explanation:
The options are:
a. Heating a solvent to help a solute dissolve.
b. Heating an isolated solid to dry it.
c. Heating water to boiling for a water bath.
d. Heating a crucible to remove water from a hydrate.
The procedure that can be performed on a hot plate are:
a. Heating a solvent to help a solute dissolve.
b. Heating an isolated solid to dry it.
c. Heating water to boiling for a water bath.
It should be noted that the hot plate cannot be used for heating of crucible in order to remove water from a hydrate. It is not advisable for someone to heat any silica or ceramic objects on a hot plate.
Therefore, heating a crucible to remove water from a hydrate is the correct option.
<span>100.
ppb of chcl3 in drinking water means 100 g of CHCl3 in 1,000,0000,000 g of water
Molarity, M
M = number of moles of solute / volume of solution in liters
number of moles of solute = mass of CHCl3 / molar mass of CHCl3
molar mass of CHCl3 = 119.37 g/mol
number of moles of solute = 100 g / 119.37 g/mol = 0.838 mol
using density of water = 1 g/ ml => 1,000,000,000 g = 1,000,000 liters
M = 0.838 / 1,000,000 = 8.38 * 10^ - 7 M <----- answer
Molality, m
m = number of moles of solute / kg of solvent
number of moles of solute = 0.838
kg of solvent = kg of water = 1,000,000 kg
m = 0.838 moles / 1,000,000 kg = 8.38 * 10^ - 7 m <----- answer
mole fraction of solute, X solute
X solute = number of moles of solute / number of moles of solution
number of moles of solute = 0.838
number of moles of solution = number of moles of solute + number of moles of solvent
number of moles of solvent = mass of water / molar mass of water = 1,000,000,000 g / 18.01528 g/mol = 55,508,435 moles
number of moles of solution = 0.838 moles + 55,508,435 moles = 55,508,436 moles
X solute = 0.838 / 55,508,435 = 1.51 * 10 ^ - 8 <------ answer
mass percent, %
% = (mass of solute / mass of solution) * 100 = (100g / 1,000,000,100 g) * 100 =
% = 10 ^ - 6 % <------- answer
</span>
Answer:
The answer to your question is C₃H₆O
Explanation:
Data
mass of sample = 23.2 g
mass of carbon dioxide = 52.8 g
mass of water = 21.6 g
empirical formula = ?
Process
1.- Calculate the mass and moles of carbon
44 g of CO₂ --------------- 12 g of C
52.8 g --------------- x
x = (52.8 x 12)/44
x = 633.6/44
x = 14.4 g of C
12 g of C ------------------ 1 mol
14.4 g of C --------------- x
x = (14.4 x 1)/(12)
x = 1.2 moles of C
2.- Calculate the grams and moles of Hydrogen
18 g of H₂O --------------- 2 g of H
21.6 g of H₂O ------------- x
x = (21.6 x 2) / 18
x = 2.4 g of H
1 g of H -------------------- 1 mol of H
2.4 g of H ----------------- x
x = (2.4 x 1)/1
x = 2.4 moles of H
3.- Calculate the grams and moles of Oxygen
Mass of Oxygen = 23.2 - 14.4 - 2.4
= 6.4 g
16 g of O ---------------- 1 mol
6.4 g of O -------------- x
x = (6.4 x 1)/16
x = 0.4 moles of Oxygen
4.- Divide by the lowest number of moles
Carbon = 1.2 / 0.4 = 3
Hydrogen = 2.4/ 0.4 = 6
Oxygen = 0.4 / 0.4 = 1
5.- Write the empirical formula
C₃H₆O
<h3>
Answer:</h3>
0.699 mole CaCl₂
<h3>
Explanation:</h3>
To get the number of moles we use the Avogadro's number.
Avogadro's number is 6.022 x 10^23.
But, 1 mole of a compound contains 6.022 x 10^23 molecules
In this case;
we are given 4.21 × 10^23 molecules of CaCl₂
Therefore, to get the number of moles
Moles = Number of molecules ÷ Avogadro's constant
= 4.21 × 10^23 molecules ÷ 6.022 x 10^23 molecules/mole
= 0.699 mole CaCl₂
Hence, the number of moles is 0.699 mole of CaCl₂
