Answer:
Calculate the mass percent of a potassium nitrate solution when 15.0 g KNO3 is dissolved in 250 g
of water.
2. Calculate the mass percent of a sodium nitrate solution when 150.0 g NaNO3 is dissolved in 500 mL
of water. Hint: 1 mL water = 1 g water
3. Calculate the weight of table salt needed to make 670 grams of a 4.00% solution.
4. How many grams of solute are in 2,200 grams of a 7.00% solution?
5. How many grams of sodium chloride are needed to prepare 6,000 grams of a 20% solution?
Mass Percent = Grams of Solute
Grams of Solution X 100%
100%
Grams of Solute = Grams of Solution X Mass Percent
= 26.8 grams NaCl
= 670 grams X 4.00%
100%
100%
Grams of Solute = Grams of Solution X Mass Percent
= 154 grams solute
= 2,200 grams X 7.00%
100%
100%
Grams of Solute = Grams of Solution X Mass Percent
= 1,200 grams NaCl
= 6,000 grams X 20.0%
100%
Explanation:
Answer:
C) 107 g
Explanation:
Step 1: Calculate the molar mass of Ca(NO₃)₂
We can calculate the molar mass of Ca(NO₃)₂ by adding the masses of its elements.
M = 1 × Ca + 2 × N + 2 × 3 × O
M = 1 × 40.08 g/mol + 2 × 14.01 g/mol + 6 × 16.00 g/mol
M = 164.10 g/mol
Step 2: Calculate the mass corresponding to 0.650 moles of Ca(NO₃)₂
We multiply the number of moles by the molar mass.
0.650 mol × 164.10 g/mol = 107 g
Answer:
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Explanation:
The balanced chemical reaction to obtain water from SnO₂ is:
The mole ratio is:

Find the number of moles equivalent to 1.20× 10²¹ molecules of water, using Avogadro's number:

From the mole ratio, the number of moles of SnO₂ are half the number of moles of water. That is:
- 0.0019927 moles / 2 = 0.00099635 moles of SnO₂
Use the molar mass of SnO₂ to convert the number of moles to grams:
- molar mass of SnO₂ = 150.71g/mol
- mass of SnO₂ = 0.00099635mol × 150.71 g/mol = 0.150 grams.
The answer must be reported with 3 significant figures.
Because their atoms have the same number of electrons in the highest occupied energy level
The rate of the reaction usually depends on the concentration of the reactants. We have to reactants in this reaction, sulfuric acid and sodium thiosulfate. Let's look at the values that were recorded.
The volume of sulfuric acid that is added is constant, but the volume of sodium thiosulfate is not. It decreases and the volume of water increases, so we are diluting the sodium thiosulfate. The concentration of one reactant is decreasing. So the rate of the reaction is also decreasing. Then the time that it takes for the cross to become invisible should increase.
Answer: the time should increase.