A doubly charged ion (charge 2e) with velocity 6.9 × 106 m/s moves in a circular path of diameter 60.0 cm in a magnetic field of 0.80 T in a mass spectrometer.  What is the mass of this ion? (e = 1.60 × 10-19 C)

Simplify the expression  . Assume all variables are nonzero.

If a 25.0-g sample of a nonelectrolyte is dissolved in 145.0 g of water, the resulting solution will freeze at –0.89 °C.  What is the molar mass of the nonelectrolyte?   (Kfp for water is 1.858 °C/m.) A. 76 g/mol B. 290 g/mol C. 320 g/mol D. 360 g/mol E. 520 g/mol

4. Which is the best acid to use in the preparation of a buffer with pH = 9.3? A. CH3NH2 (Kb = 3.7 × 10–4) B. NH3 (Kb = 1.8 × 10–5) C. NH2OH (Kb = 9.1 × 10–9) D. C6H5NH2 (Kb = 4.3 × 10–10)

What is the pH of a saturated solution of Fe(OH)2?  For Fe(OH)2, Ksp = 8.0 x 10–16 . a. 9.93 b. 8.37 c. 7.23 d. 9.07 e. 10.15

Simplify   . Assume the denominator is not equal zero.

Write a balanced half-reaction for the reduction of CrO42–(aq) to Cr(OH)3(s) in a basic solution. a. CrO42–(aq) + 3 OH–(aq) + 3 e– -> Cr(OH)3(s) + 2 O2(g) b. CrO42–(aq) + 3 H+(aq) + 3 e– -> Cr(OH)3(s) c. CrO42–(aq) + 3 H+(aq) -> Cr(OH)3(s) + 2 e– d. CrO42–(aq) + 4 H2O(l) + 3 e– -> Cr(OH)3(s) + 5 OH–(aq) e. CrO42–(aq) + 3 OH–(aq) -> Cr(OH)3(s) + 2 O2(g)

Find the degree of the following polynomial    .

Which of the following is correct for the condensation of gaseous water at 88°C?  The normal boiling point of water is 100°C. a. ΔH < 0, ΔS > 0, and ΔG > 0. b. ΔH < 0, ΔS < 0, and ΔG < 0. c. ΔH > 0, ΔS < 0, and ΔG < 0. d. ΔH = 0, ΔS = 0, and ΔG < 0. e. ΔH > 0, ΔS > 0, and ΔG > 0.

What is the pH of the final solution when 25 mL of 0.021 M HCl has been added to 35 mL of 0.036 M HCl at 25°C? a. 3.3 b. 1.9 c. 1.5 d. 2.7 e. 3.5