Question

8. One serving of cheese (10 g) provides 7% of recommended daily allowance (RDA) of Ca. The RDA value for Ca is 1000 mg. What is the concentration of Ca in ppb in one serving of cheese? $\text{ppb} = \frac{g \text{ solute}}{g \text{ solvent}} \times 10^9$ $\frac{1000 \text{ mg}}{10 \text{ g}}$ $\frac{0.01 \text{ kg}}{10 \text{ g}} \times 10^9$ $= 700,000 \text{ ppb}$

          8. One serving of cheese (10 g) provides 7% of recommended daily allowance (RDA) of Ca. The
RDA value for Ca is 1000 mg. What is the concentration of Ca in ppb in one serving of cheese?
$\text{ppb} = \frac{g \text{ solute}}{g \text{ solvent}} \times 10^9$
$\frac{1000 \text{ mg}}{10 \text{ g}}$
$\frac{0.01 \text{ kg}}{10 \text{ g}} \times 10^9$
$= 700,000 \text{ ppb}$

8. One serving of cheese (10 g) provides 7% of recommended daily allowance (RDA) of Ca. The
RDA value for Ca is 1000 mg. What is the concentration of Ca in ppb in one serving of cheese?
ppb = (g solute)/(g solvent)× 10^9
(1000 mg)/(10 g)
(0.01 kg)/(10 g)× 10^9
= 700,000 ppb

Added by Isabella G.

Chemistry: Structure and Properties

Nivaldo Tro 2nd Edition

Instant Answer

Solved by Expert Snehal J

Step 1

07 × 1000 mg = 70 mg of Ca per 10 g serving. Show more…

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Why is this the answer? Did my teacher mark it right even though it is incorrect? One serving of cheese (10 g) provides 7% of the recommended daily allowance (RDA) of Ca. The ppm = gSolute/gSovent x 10^6. Therefore, 1000 mg = 0.07 x 10^6 mg. Solving for gSolute, we get 700,000 ppm.