Multiple Choice
What is the mass percent (m/m%) of a solution if 20 grams of solute is dissolved in 80 grams of solvent?
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3. Chemical Reactions
Mass Percent
Multiple Choice
What is the approximate percent by mass of potassium (K) in potassium bicarbonate (KHCO3)?
A
52%
B
23%
C
11%
D
39%
Verified step by step guidance1
Step 1: Identify the chemical formula of potassium bicarbonate, which is KHCO\_3, and list the atomic masses of each element involved: potassium (K), hydrogen (H), carbon (C), and oxygen (O).
Step 2: Calculate the molar mass of potassium bicarbonate by summing the atomic masses of all atoms in the formula: \( M_{KHCO_3} = M_K + M_H + M_C + 3 \times M_O \).
Step 3: Calculate the mass contribution of potassium (K) alone, which is just its atomic mass \( M_K \).
Step 4: Use the formula for percent by mass of potassium in the compound: \[ \text{Percent by mass of K} = \left( \frac{M_K}{M_{KHCO_3}} \right) \times 100\% \].
Step 5: Substitute the atomic masses into the formula and perform the division and multiplication to find the approximate percent by mass of potassium in potassium bicarbonate.
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