Answer to Question #137544 in General Chemistry for Chanel Westbrook

Question

How many grams of Br are in 335 g CaBr2?

Answer 1

Solution:

One mole of calcium bromide (CaBr₂) contains:

• one mole of calcium cations (Ca²⁺);
• two moles of bromide anions (Br⁻).

For CaBr₂: M = 199.89 g mol⁻¹

For Br: M = 79.904 g mol⁻¹

The percent composition of Br in CaBr₂ is:

(2 × 79.904 g/mol) / (199.89 g/mol) = 0.7995 or 79.95%

This means that every 100 grams of CaBr₂ contain 79.95 grams of Br.

In our case, a 335 g of CaBr₂ contains:

335 g CaBr₂ × (79.95 g Br / 100 g CaBr₂) = 267.83 g Br = 268 g Br

Answer: 268 grams of Br are in 335 g CaBr₂