how many grams of cacl2 are in 250 ml of 2.0 m cacl2? g cacl2

16.7 g CaCl₂

Step-by-step

1. Molarity definition
   2.0textM2.0\\text{M}2.0textM means 2.0textmolCaCl22.0\\text{mol CaCl}_22.0textmolCaCl2​ per 1.0textLsolution1.0\\text{L solution}1.0textLsolution.

2. Convert volume
   250textmL=0.250textL250\\text{mL}=0.250\\text{L}250textmL=0.250textL.

3. Find moles of CaCl₂

moles=2.0fracmolL×0.250textL=0.50textmol\text{moles}=2.0\\frac{\text{mol}}{\text{L}}\times 0.250\\text{L}=0.50\\text{mol}moles=2.0fracmolL×0.250textL=0.50textmol

4. Molar mass of CaCl₂
   • Ca ≈ 40.1 g/mol
   • Cl ≈ 35.5 g/mol, and there are 2 Cl atoms

MCaCl2≈40.1+2(35.5)=111.1textg/molM_{\text{CaCl}_2}\approx 40.1+2(35.5)=111.1\\text{g/mol}MCaCl2​​≈40.1+2(35.5)=111.1textg/mol

5. Convert moles to grams

mass=0.50textmol×111.1fracgmol≈55.55textg\text{mass}=0.50\\text{mol}\times 111.1\\frac{\text{g}}{\text{mol}}\approx 55.55\\text{g}mass=0.50textmol×111.1fracgmol≈55.55textg

So, for 250 mL of 2.0 M CaCl₂, the correct mass is about 55.6 g CaCl₂ (not 16.7 g).