Sig Figs and
Balancing Chemical Equations
Balancing Chemical Equations
How many significant digits are there in this number:
54.3
3
What is a solute?
Something that gets dissolved in something else.
Calculate the concentration of a solution containing 0.2 moles of solute in 500mL of solution.
C = 0.4 mols
A solution of hydrochloric acid with a concentration of 2.0 mol/L is diluted to 0.5 mol/L. If the initial volume was 500 mL, what is the final volume of the diluted solution?
V = 2L
What is v/v% of a compund that combines 162 ml of acetic acid with 454 ml of water?
35.7%
How many significant digits are there in this number:
5400
2
Explain what happens to the solubility of most gases as temperature increases.
Decreases
Determine the concentration of a solution with 25g of NaCl dissolved in 750mL of water.
C = 0.57 M
If 100 mL of a 4.0 mol/L glucose solution is diluted to 1.0 mol/L, what will be the final volume of the solution?
V = 0.4L
A 1.7 L sample of water was found to contain 54 ng of Penicillin. What is the concentration in ppt?
32 x 1012 or 32 ppt
How many significant digits are there in this number: 0.0020
4
What is the universal solvent?
Water
Find the concentration of a solution that has 0.5 moles of solute in 250mL of solution.
C = 2 M
A solution of sulfuric acid has a concentration of 3.5 mol/L. If 300 mL of this solution is diluted to 1.0 mol/L, what will be the final volume?
1L
What is w/w% of a compund that combines 232 g of acetic acid with 654 g of water?
0.355%
What is the balanced chemical equation for: FeS2 + O2 -> Fe2O3 + SO2
4FeS2 + 11O2 -> 2Fe2O3 + 8SO2
Define solubility.
Solubility is the maximum amount of solute that can dissolve in a solvent at a specific temperature or pressure.
If the concentration of a sodium chloride solution is 0.4 mol/L and the volume is 1.5 L, calculate the mass of the solute needed to prepare this solution.
35g or 40g
If 250 mL of a 6.0 mol/L potassium hydroxide solution is diluted to 2.0 mol/L, what will be the final volume of the solution?
0.8L
A 5.7 L sample of water was found to contain 64 μg of Mercury. What is the concentration in ppb?
11 x 109 or 11 ppb
What is the balanced combustion equation for methane?
CH4 + 2O2 -> CO2 + 2H2O
Write out the dissociation equation for MgCl2
MgCl2 -> Mg2+ + Cl2-
A solution of Potassium sulphate has a concentration of 1.2 mol/L and a volume of 750 mL. Determine the mass of the solute present in the solution
156.8g or 1.6 x 102 g
An ethanol solution with a concentration of 5.0 mol/L is diluted to 1.0 mol/L. If the initial volume was 400 mL, what will be the final volume after dilution?
2L
What volume of a 3.55 % W/V salt solution can be prepared using 276 g of glucose?
7770 L