2: Solutions
Solution preparation using mass concentration, molarity, and volume ratios.
Mass for a Target Concentration
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| Ethylenediaminetetraacetic acid (EDTA) | |
| Volume | 30.0 mL |
| Concentration | 15.0 mg/mL |
| Molecular weight | 292.24 g/mol |
| State | Solid powder at room temperature |
How many milligrams (mg) of ethylenediaminetetraacetic acid (EDTA) would you need to make 30.0 mL of a 15.0 mg/mL EDTA solution?
Note: answers need to be within 1% of the correct number to be correct.
Mass for Weight/Volume Solutions
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| Magnesium chloride (MgCl2) | |
| Volume | 400 mL |
| Concentration | 5% (w/v) |
| Molecular weight | 95.21 g/mol |
| State | Solid powder at room temperature |
How many grams (g) of magnesium chloride (MgCl2) you would need to make 400 mL of a 5% (w/v) MgCl2 solution?
Note: answers need to be within 5% of the correct number to be correct.
Mass for Solutions Using Molarity and Molecular Weight
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| Sodium bicarbonate (NaHCO3) | |
| Volume | 390 mL |
| Concentration | 4 mM |
| Molecular weight | 84.01 g/mol |
| State | Solid powder at room temperature |
How many milligrams (mg) of sodium bicarbonate (NaHCO3) would you need to make 390 mL of a 4 mM NaHCO3 solution?
Note: answers need to be within 1% of the correct number to be correct.
Solute Volume for Percent Volume/Volume Solutions
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| isopropyl alcohol | |
| Volume | 250 mL |
| Concentration | 20% (v/v) |
| Molecular weight | 60.10 g/mol |
| State | Liquid at room temperature |
How many milliliters (mL) of isopropyl alcohol you would need to make 250 mL of a 20% (v/v) isopropyl alcohol solution?
Note: answers need to be within 2% of the correct number to be correct.