A solution of sodium cyanide NACN has a PH of 12.10. How many grams of NACN are in 425ml of solution with the same PH?
Please helps me to solve it for me
How to calculate PH 1.9 = 0.0126M Why?
How to calculate PH 1.8 = ?
How to calculate PH 20 = ?
How to calculate PH 21 = ?
Pls helps me
pH = -log(H^+)
1.9 = -log(H^+)
-1.9 = log(H^+).
(H^+) = 0.01259 which rounds to 0.126
The others are done the same way.
I do not still understand how to calculate PH 1.9 = 0.0126M
I want step by step to calculate for me.
Thank you for your help.
To solve this question, we need to use the concept of molarity and the equation that relates pH to the concentration of a solution. Here's how we can solve it step by step:
Step 1: Determine the concentration of sodium cyanide (NaCN) in the solution. Since the pH is given, we can use the equation:
pH = -log[H+]
Since sodium cyanide is a base, we need to convert the pH to pOH before finding the concentration. The pOH can be calculated using the equation:
pOH = 14 - pH
Thus,
pOH = 14 - 12.10
pOH = 1.90
Step 2: Calculate the hydroxide ion concentration [OH-]. Using the equation:
pOH = -log[OH-]
Rearranging for [OH-]:
[OH-] = 10^-pOH
[OH-] = 10^-1.90
[OH-] = 0.01259 M
Step 3: Convert molarity to moles per liter. Since we have the concentration in moles per liter (M), we can convert it to moles by multiplying by the volume (in liters):
0.01259 M × (425 ml / 1000 ml/L) = 5.35 × 10^-3 moles
Step 4: Convert moles to grams. To convert moles to grams, we need to know the molar mass of NaCN. The molar mass of NaCN is:
Na: 22.99 g/mol
C: 12.01 g/mol
N: 14.01 g/mol
Adding these values:
22.99 g/mol + 12.01 g/mol + 14.01 g/mol = 49.01 g/mol
The molar mass of NaCN is 49.01 g/mol.
To find the grams, we multiply:
5.35 × 10^-3 moles × 49.01 g/mol = 0.262 grams
Therefore, there are approximately 0.262 grams of NaCN in 425 ml of solution with a pH of 12.10.
pH = 12.10
pH + pOH = pKw = 14
Substitute and sole for pOH. You should get 1.9 for pOH, then
pOH = -log(OH^-) and (OH^-) = 0.0126M.
0.0126M mans 0.0126 mols/L soln. For 425 mL you will have 0.0126 mol x (425/1000) = about 0.00536 mols. Then grams = mols x molar mass NaCN.