General Chemistry Answers

It is intended to prepare 2 L of a 0.170 M NaOH solution. For this, NaOH is available 54. 8% ± 0. 3% (m/m), with relative density 1.52 ± 0.01. The pipette used has a ±0.10ml error. The error of the volumetric balloon is 0.005 L. Determine the volume a pipette. Establish the formula that allows finding this value. Invert the formula to obtain the final concentration as a function of the remaining variables. Estimate the error associated with

predicted final concentration from the previous formula

Balance h2so4 yielded h2o plus so3

A metallurgist wants to chromium plate his car’s hood ornament. The ornament has a

surface area of 13.64 in2. He wants the chromium plating to be 0.0040 in thick.

(a) How many grams of chromium (d 5 7.19 g/cm3) are required?

(b) If a current of 9.00 amperes is used, how long will it take to plate the ornament using

a solution of CrCl3 as a chromium source? (Assume 100% efciency.)

Methanol, CH₃OH, is produced in the reaction: CO₂ + 2H₂ → CH₃OH. How many moles of methanol can be produced when 4.5 mol of CO reacts with 7.2 mol H₂?

calculate the mass of 6.022 x 10^23 particles of CaSO4

Describe an experiment to show that there is increase in mass when magnesium is burned in air

Consider the following reactions:

          3 Ni 2+(aq)  + 2Cr(OH)3 (s) + 10 OH –(aq)    →   3 Ni (s) + 2 CrO4 –2 (aq) + 8 H2O (l)

A) What is the value for n for this reactions?

B) Calculate the standard Gibbs Free-Energy

C) How long does it take a current of 5 A to deposit  95 g of nickel?

Calculate the Gibbs Free-Energy and the standard Gibbs Free-

       Energy by the cell in the given cell notation:       Zn(s) |Zn2+(aq) || H+(aq)| H2(g) |Pt (s)

          When [Zn+2] = 4.0 x 10 -3 M, [H2] = 0.010 M, [H+] = 1.0 M

4. Consider the following reactions:

          3 Ni 2+(aq)  + 2Cr(OH)3 (s) + 10 OH –(aq)    →   3 Ni (s) + 2 CrO4 –2 (aq) + 8 H2O (l)