Chemistry, 18.09.2019 05:30 tallen21

Asolid piece of aluminum (51.0 g) was added to a solution of sodium hydroxide (84.1 g) in water, a balanced equation for this reaction is shown below:
2 naoh(aq)+ 2 al(s)+ 2 h2o → 2 naalo2(aq)+ 3 h2(g)
(a) which reagent is completely consumed by the reaction?
(b) after the reaction is completed, what is the mass of the reagent that remains? (c) what mass of hydrogen gas is produced?

Answers: 1

Show answers

Answers

$M_{Al}=26,98\frac{g}{mol}\\
m=51g\\\\
n=\frac{m}{M_{Al}}=\frac{51g}{26,97\frac{g}{mol}}\approx1,89mol\\\\\\
M_{NaOH}=39,4\frac{g}{mol}\\
m=84,1g\\\\
n=\frac{m}{M_{NaOH}}=\frac{84,1g}{39,4\frac{g}{mol}}\approx2,14mol$

2 NaOH(aq)+ 2 Al(s)+ 2 H₂O → 2 NaAlO₂(aq)+ 3 H₂(g)
2mol : 2mol : 3mol
2,14mol : 1,89mol : 2,835mol
remains completely consumed
2,14-1,89=0,25mol

A) Al

B)

$M_{NaOH}=39,4\frac{g}{mol}\\
n=0,25mol \Rightarrow \ \ \ m=n*M_{NaOH}=0,25mol*39,4\frac{g}{mol}=9,85g$

C)
$n=2,835mol\\
M_{H_{2}}=2,02\frac{g}{mol} \Rightarrow \ \ \ m=n*M_{H_{2}}=2,835mol*2,02\frac{g}{mol} \approx 5,73g$

Answer from: Quest

D. is the answer hope that you

Answer from: Quest

remember that hf is only the energy of one photon. not two. not three. one. 1) 5.12 * 10^3 photons find the energy of one photon, then determine how many photons are needed to reach the sensitivity. e = hf = (6.626 * 10^-34 js)(5.95 * 10^19 hz) = 3.94247 * 10^-14 j per photon (2.02 * 10^-10 j) / (3.94247 * 10^-14 j/photon) = 5123.69149 photons round to three sig figs. 2) 5.77 * 10^-17 j energy of pulse = energy per photon * number of photons = hfn = (6.626 * 10^-34 js)(1.66 * 10^13 hz)(5250) = 5.774559 * 10^-17 j round to three sig figs. 3) 4.07 * 10^8 kj/mol 10^12 pm = 1 m c = fλ f = c/λ e = hf = hc/λ = [(6.626 * 10^-34 js)(3.00 * 10^8 m/s) / (2.94 * 10^-12 m)](1 kj/1000 j)(6.02 * 10^23 photons/mol) = 40702571.4 kj/mol round to three sig figs. 4) 9.94 * 10^-1 m e = hc/λ λ = hc / e = (6.626 * 10^-34 js)(3.00 * 10^8 m/s) / (2.00 * 10^-25 j) = 0.9939 m round to three sig figs. 5) 9.06 * 10^3 photons energy of pulse = energy per photon * number of photons number of photons = energy of pulse / energy per photon = energy of pulse / (hf) = (3.87 * 10^-13 j) / [(6.626 * 10^-34 js)(6.45 * 10^16 hz)] = 9055.23695 photons round to three sig figs. 6) 2.78 * 10^-15 j this is problem 1, except in reverse. sensitivity = minumum number of photons * energy per photon = (5930)(6.626 * 10^-34 js)(7.077 * 10^14 hz) = 2.78070758 × 10^-15 j round to three sig figs.

Another question on Chemistry

Chemistry, 22.06.2019 15:00

Describe what happens to the molecules as water goes from ice to liquid to vapor. be sure to explain what happens to the temperature during the phase changes.

Answers: 2

Answer

Chemistry, 22.06.2019 19:30

Chlorine and water react to form hydrogen chloride and oxygen, like this: 2cl2 (g) + 2h2o (g) → 4hcl (g) + o2 (g) also, a chemist finds that at a certain temperature the equilibrium mixture of chlorine, water, hydrogen chloride, and oxygen has the following composition: compound concentration at equilibrium cl2 0.55m h2o 0.57m hcl 0.53m o2 0.34m calculate the value of the equilibrium constant kc for this reaction. round your answer to 2 significant digits.

Answers: 2

Answer

Chemistry, 22.06.2019 22:30

What is the work done by the electric force to move a 1 c charge from a to b?

Answers: 2

Answer

Chemistry, 23.06.2019 04:00

What two categories of toxins were present in the air at dish,texas as a result of the gas pipelines that pass through the area

Answers: 1

Answer

You know the right answer?

Asolid piece of aluminum (51.0 g) was added to a solution of sodium hydroxide (84.1 g) in water, a b...