Cr{3+} + 3 NaF → CrF3 +
3 Na{+} <span>
First calculate the total mols of NaF.
(0.063 L) x (1.50 mol/L NaF) = 0.0945 mol NaF total </span>
Using stoichiometric
ratio:
<span>0.0945 mol NaF * (1 mol Cr3+ / 3 mol NaF) * (51.9961 g Cr3+/mol) =
1.6379 g Cr3+</span>
<span>0.925 grams if using hydrochloric acid in the reaction.
0.462 grams if using sulfuric acid in the reaction.
0.000 grams if using nitric acid in the reaction.
Assuming you're using HCl or a similar acid for this reaction, the equation for the reaction is:
Zn + 2 HCl ==> ZnCl2 + H2
So each mole of zinc used, produces 1 mole of hydrogen gas, or 2 moles of hydrogen atoms. So we need to look up the atomic weights of both zinc and hydrogen.
Atomic weight zinc = 65.38
Atomic weight hydrogen = 1.00794
Moles zinc = 30.0 g / 65.38 g/mol = 0.458855919 mol
Since we produce 2 moles of hydrogen atoms per mole of zinc, multiply by 2 and the atomic weight of hydrogen to get the mass of hydrogen produced. So
0.458855919 * 2 * 1.00794 = 0.92499847 grams.
Rounding to 3 significant figures gives 0.925 grams.
To show the assumption of the acid used, the balanced equation for sulfuric acid would be
Zn2 + H2SO4 ==> Zn(SO4)2 + H2
Which means that for every mole of zinc used, 1 mole of hydrogen gas is generated (half that produced via hydrochloric acid).
If nitric acid were used, the reaction is
4Zn + 10HNO3 ==> 4Zn(NO3)2 + N2O + 5H2O
Which means that NO hydrogen gas is generated.
The only justification for assuming hydrochloric acid is used is that it's a fairly common acid that's easy to obtain. But as shown above with 2 alternative acids, the amount of hydrogen gas generated is very dependent upon the exact chemical reaction occurring and asking "How many grams of hydrogen are produced if 30.0 g of zinc reacts?" is a rather silly question unless you specify EXACTLY what the reaction is.</span>
Answer:
1.822 g of magnesium hydroxide would be produced.
Explanation:
Balanced reaction: 
Compound Molar mass (g/mol)
NaOH 39.997
95.211
58.3197
So, 2.50 g of NaOH = 
mol of NaOH = 0.0625 mol of NaOH
4.30 g of = 
mol of = 0.0452 mol of
According to balanced equation-
2 mol of NaOH produce 1 mol of
So, 0.0625 mol of NaOH produce 
mol of NaOH or 0.03125 mol of NaOH
1 mol of produces 1 mol of
So, 0.0452 mol of produce 0.0452 mol of
As least number of moles of are produced from NaOH therefore NaOH is the limiting reagent.
So, amount of would be produced = 0.03125 mol
= 
g
= 1.822 g
D has a total of four significant figures.
Answer:
About 0.08486 moles
Explanation:
PV=nRT, when P is the pressure in atmospheres, V is the volume in liters, n is the number of moles, R is the universal gas constant, and T is the temperature in Kelvin.
moles
Hope this helps!
