I need help with these problems ASAP:
I need help setting these problems up: pleas!!
(1)Calculate the volume of 1.87 M NaI that would be needed to precipitate all of the Hg+2 ion from 199 mL of a 1.96 M Hg(NO3)2. The equation for the reaction is
2NaI (aq) + Hg(NO3)2 (aq) ---> HgI2 (2) +2NaNO3 (aq)
(2)Calculate the volume of 1.91M sulfuric acid that would be needed to neutralize 42.9 mL of a 1.24 M aqueous ammonia solution. The equation for the reaction is:
H2SO4 (aq) +2NH3 (aq) ---> 2NH4+ (aq) + SO4-2 (aq)
#1. You have the equation.
2. Convert 199 mL of 1.96 M Hg(NO3)2 to moles. moles = M x L.
3. Using the coefficients in the balanced equation, convert moles Hg(NO3)2 to moles NaI.
4. Now convert moles NaI to mL.
M = moles/L. YOu have M and moles, calculate L and convert to mL.
The second problem is done the same way.
To solve these problems, we can use the concept of stoichiometry, which involves calculating the relationship between the reactants and products in a chemical reaction.
For problem (1), to determine the volume of NaI needed, we can use the molar ratio between NaI and Hg(NO3)2 from the balanced chemical equation.
Step 1: Write down the given information:
- Molarity of Hg(NO3)2: 1.96 M
- Volume of Hg(NO3)2: 199 mL
Step 2: Convert the volume of Hg(NO3)2 into liters:
199 mL = 199/1000 L = 0.199 L
Step 3: Use the molar ratio from the balanced chemical equation:
2 moles of NaI react with 1 mole of Hg(NO3)2
Step 4: Calculate the number of moles of Hg(NO3)2:
moles of Hg(NO3)2 = Molarity * Volume in liters
moles of Hg(NO3)2 = 1.96 M * 0.199 L = 0.39004 moles
Step 5: Use the molar ratio to find the number of moles of NaI:
moles of NaI = (moles of Hg(NO3)2) * (2 moles of NaI / 1 mole of Hg(NO3)2)
moles of NaI = 0.39004 * 2 = 0.78008 moles
Step 6: Calculate the volume of NaI:
Volume of NaI = (moles of NaI) / (Molarity of NaI)
Volume of NaI = 0.78008 moles / 1.87 M = 0.416 L = 416 mL
Therefore, the volume of 1.87 M NaI needed to precipitate all of the Hg+2 ions is 416 mL.
For problem (2), we will follow a similar approach.
Step 1: Write down the given information:
- Molarity of sulfuric acid (H2SO4): 1.91 M
- Volume of ammonia solution: 42.9 mL
Step 2: Convert the volume of ammonia solution into liters:
42.9 mL = 42.9/1000 L = 0.0429 L
Step 3: Use the molar ratio from the balanced chemical equation:
1 mole of H2SO4 reacts with 2 moles of NH3
Step 4: Calculate the number of moles of NH3:
moles of NH3 = Molarity * Volume in liters
moles of NH3 = 1.24 M * 0.0429 L = 0.053196 moles
Step 5: Use the molar ratio to find the number of moles of H2SO4:
moles of H2SO4 = (moles of NH3) * (1 mole of H2SO4 / 2 moles of NH3)
moles of H2SO4 = 0.053196 * 1/2 = 0.026598 moles
Step 6: Calculate the volume of H2SO4:
Volume of H2SO4 = (moles of H2SO4) / (Molarity of H2SO4)
Volume of H2SO4 = 0.026598 moles / 1.91 M = 0.013921 L = 13.921 mL
Therefore, the volume of 1.91 M sulfuric acid needed to neutralize the ammonia solution is 13.921 mL.