for each of the following acid-base reactions calculate the mass (in grams) of each acid necessary to completely react with and neutralize 4.85g of the base solution
1)2HNO3(aq)+ Ca(OH)2 (aq)> 2h20(l)+ Ca(NO3)2
2) H2SO4(aq)+ 2KOH(aq)---> 2H2O(l)+ K2SO4
1)
a. Write and balance the equation which you have.
b. mols base Ca(OH)2 = grams/molar mass = ?
c. Using the coefficients in the balanced equation, convert mols base to mols acid.
d. Now convert mols acid to grams = mols acid x molar mass acid.
To calculate the mass of each acid necessary to neutralize the base solution, we need to use stoichiometry and the molar mass of the compounds involved in the reactions. Here are the steps to calculate the mass of each acid:
1) HNO3 + Ca(OH)2 -> H2O + Ca(NO3)2
Step 1: Determine the molar mass of the base (Ca(OH)2):
The molar mass of Ca(OH)2 is calculated as follows:
Ca = 40.08 g/mol (1 atom of Ca)
O = 16.00 g/mol (2 atoms of O)
H = 1.01 g/mol (2 atoms of H)
So, the molar mass of Ca(OH)2 is:
40.08 g/mol + 2(16.00 g/mol) + 2(1.01 g/mol) = 74.08 g/mol
Step 2: Determine the molar mass of the acid (HNO3):
The molar mass of HNO3 is calculated as follows:
H = 1.01 g/mol (1 atom of H)
N = 14.01 g/mol (1 atom of N)
O = 16.00 g/mol (3 atoms of O)
So, the molar mass of HNO3 is:
1.01 g/mol + 14.01 g/mol + 3(16.00 g/mol) = 63.02 g/mol
Step 3: Calculate the moles of the base (Ca(OH)2):
moles = mass / molar mass
moles = 4.85 g / 74.08 g/mol ≈ 0.065 moles
Step 4: Calculate the moles of the acid (HNO3):
From the balanced equation, the stoichiometric ratio is 2:1 between HNO3 and Ca(OH)2. So, for every 2 moles of HNO3, we react with 1 mole of Ca(OH)2.
moles of HNO3 = 0.065 moles x (2 moles HNO3 / 1 mole Ca(OH)2) = 0.13 moles
Step 5: Calculate the mass of HNO3:
mass = moles x molar mass
mass = 0.13 moles x 63.02 g/mol = 8.19 g (rounded to two decimal places)
Therefore, you would need approximately 8.19 grams of HNO3 to neutralize 4.85 grams of the base solution in this reaction.
2) H2SO4 + 2KOH -> 2H2O + K2SO4
The steps to calculate the mass of H2SO4 are similar to the previous example:
Step 1: Determine the molar mass of the base (KOH):
K = 39.10 g/mol (1 atom of K)
O = 16.00 g/mol (1 atom of O)
H = 1.01 g/mol (1 atom of H)
So, the molar mass of KOH is:
39.10 g/mol + 16.00 g/mol + 1.01 g/mol = 56.11 g/mol
Step 2: Determine the molar mass of the acid (H2SO4):
H = 1.01 g/mol (2 atoms of H)
S = 32.07 g/mol (1 atom of S)
O = 16.00 g/mol (4 atoms of O)
So, the molar mass of H2SO4 is:
2(1.01 g/mol) + 32.07 g/mol + 4(16.00 g/mol) = 98.09 g/mol
Step 3: Calculate moles of the base (KOH):
moles = mass / molar mass
moles = 4.85 g / 56.11 g/mol ≈ 0.087 moles
Step 4: Calculate moles of the acid (H2SO4):
According to the balanced equation, the stoichiometric ratio between H2SO4 and KOH is 1:2. So, for every 1 mole of H2SO4, we need 2 moles of KOH.
moles of H2SO4 = 0.087 moles x (1 mole H2SO4 / 2 moles KOH) = 0.044 moles
Step 5: Calculate the mass of H2SO4:
mass = moles x molar mass
mass = 0.044 moles x 98.09 g/mol = 4.32 g (rounded to two decimal places)
Therefore, you would need approximately 4.32 grams of H2SO4 to neutralize 4.85 grams of the base solution in this reaction.
To calculate the mass of each acid required to react with and neutralize 4.85g of the base solution, we will use stoichiometry.
1) 2HNO3(aq) + Ca(OH)2(aq) → 2H2O(l) + Ca(NO3)2(aq)
The balanced equation shows that the molar ratio between HNO3 and Ca(OH)2 is 2:1. Therefore, we need twice the amount of moles of HNO3 compared to Ca(OH)2 to react completely.
Step 1: Calculate the molar mass of Ca(OH)2.
Ca = 1 atomic mass unit (amu)
O = 16 amu (4 * 16 = 64 amu)
H = 1 amu (2 * 1 = 2 amu)
Total molar mass of Ca(OH)2 = 40 + 16 + 2 = 58 amu
Step 2: Calculate the number of moles of Ca(OH)2 in the 4.85g sample.
Number of moles = mass / molar mass
Number of moles of Ca(OH)2 = 4.85g / 58g/mol
Step 3: Calculate the mass of HNO3 required using the mole ratio from the balanced equation.
Molar mass of HNO3 = 63 g/mol
Number of moles of HNO3 = 2 * Number of moles of Ca(OH)2
Mass of HNO3 required = Number of moles of HNO3 * Molar mass of HNO3
2) H2SO4(aq) + 2KOH(aq) → 2H2O(l) + K2SO4(aq)
The balanced equation shows that the molar ratio between H2SO4 and KOH is 1:2. Therefore, we need twice the amount of moles of KOH compared to H2SO4 to react completely.
Step 1: Calculate the molar mass of H2SO4.
H = 1 amu (2 * 1 = 2 amu)
S = 32 amu
O = 16 amu (4 * 16 = 64 amu)
Total molar mass of H2SO4 = 2 + 32 + 64 = 98 amu
Step 2: Calculate the number of moles of H2SO4 in the 4.85g sample.
Number of moles = mass / molar mass
Number of moles of H2SO4 = 4.85g / 98g/mol
Step 3: Calculate the mass of KOH required using the mole ratio from the balanced equation.
Molar mass of KOH = 56 g/mol
Number of moles of KOH = 2 * Number of moles of H2SO4
Mass of KOH required = Number of moles of KOH * Molar mass of KOH
By following these steps, you will be able to calculate the mass of each acid required to completely react with and neutralize 4.85g of the base solution for the given acid-base reactions.