[antony22]

I am in need of some serious help with this buffer. I am using 24.5 mL of 0.1 M sodium citrate solution with 25.5 mL citric acid to make pH 4.6 buffer. The problem is I need to manufacture the sodium citrate myself and I'm not sure how I can create a solution with the appropriate amount of concentration and volume.

I know you can make sodium citrate by reacting citric acid with NaOH or sodium bicarb but I'm not sure how to calculate the required amounts of each needed to make 25.5 mL + of 0.1 M sodium citrate. Any ideas?

[maivu]

I am in need of some serious help with this buffer. I am using 24.5 mL of 0.1 M sodium citrate solution with 25.5 mL citric acid to make pH 4.6 buffer. The problem is I need to manufacture the sodium citrate myself and I'm not sure how I can create a solution with the appropriate amount of concentration and volume.

I know you can make sodium citrate by reacting citric acid with NaOH or sodium bicarb but I'm not sure how to calculate the required amounts of each needed to make 25.5 mL + of 0.1 M sodium citrate. Any ideas?

Ok, finally, you just need to know how to calculate the required amount each chemicals needed to make 25.5 ml of sodium citrate 0.1M or 0.1 mol/ dm³.

Volume of sodium citrate: 25.5 ml = 0.025 dm³
Concentration of sodium citrate: C_M = 0.1
Number of mole of sodium citrate: n = V*C_M = 0.025*0.1 = 0.0025 moles.

Sodium citrate can be produced by the reaction between sodium hydroxide and citric acid with the ratio:

3 Sodium hydroxide + 1 citric acid  1 sodium citrate + 3 water
0.00675                    0.0025                       0.0025                                (moles)
3 volumes                 1 volume                  1 volume              3 volumes                       

In here, I wonder if you can give me further information about the amount of sodium hydroxide and citric acid you have. (volumes and concentrations).

Hints: From volumes and concentration of sodium hydroxide and citric acid, you can calculate the number of moles needed for each reactants.

Hope that it helped. 

[antony22]

Ok, finally, you just need to know how to calculate the required amount each chemicals needed to make 25.5 ml of sodium citrate 0.1M or 0.1 mol/ dm³.

Volume of sodium citrate: 25.5 ml = 0.025 dm³
Concentration of sodium citrate: C_M = 0.1
Number of mole of sodium citrate: n = V*C_M = 0.025*0.1 = 0.0025 moles.

Sodium citrate can be produced by the reaction between sodium hydroxide and citric acid with the ratio:

3 Sodium hydroxide + 1 citric acid  1 sodium citrate + 3 water
0.00675                    0.0025                       0.0025                                (moles)
3 volumes                 1 volume                  1 volume              3 volumes                       

In here, I wonder if you can give me further information about the amount of sodium hydroxide and citric acid you have. (volumes and concentrations).

Hints: From volumes and concentration of sodium hydroxide and citric acid, you can calculate the number of moles needed for each reactants.

Hope that it helped. 

I made a mistake in the post I am planning to make 24.5 mL of sodium citrate. I have 0.1 M or 1 M sodium hydroxide and citric acid available to me. I suppose using one of those concentrations I could find the volumes of sodium hydroxide and citric acid I need. Is that correct?

[maivu]

Ok, finally, you just need to know how to calculate the required amount each chemicals needed to make 25.5 ml of sodium citrate 0.1M or 0.1 mol/ dm³.

Volume of sodium citrate: 25.5 ml = 0.025 dm³
Concentration of sodium citrate: C_M = 0.1
Number of mole of sodium citrate: n = V*C_M = 0.025*0.1 = 0.0025 moles.

Sodium citrate can be produced by the reaction between sodium hydroxide and citric acid with the ratio:

3 Sodium hydroxide + 1 citric acid  1 sodium citrate + 3 water
0.00675                    0.0025                       0.0025                                (moles)
3 volumes                 1 volume                  1 volume              3 volumes                       

In here, I wonder if you can give me further information about the amount of sodium hydroxide and citric acid you have. (volumes and concentrations).

Hints: From volumes and concentration of sodium hydroxide and citric acid, you can calculate the number of moles needed for each reactants.

Hope that it helped. 

I made a mistake in the post I am planning to make 24.5 mL of sodium citrate. I have 0.1 M or 1 M sodium hydroxide and citric acid available to me. I suppose using one of those concentrations I could find the volumes of sodium hydroxide and citric acid I need. Is that correct?

Ok, sorry. Actually, it was my mistake as well. So let me make it clear this way:

Sodium citrate (1): V₁ = 24.5 ml = 0.0245 dm³;  C₁= 0.1 M
Sodium hydroxide(2): V₂ =?                                           ; C₂ = 0.1 M
Citric acid (3):           V₃ = ?                                          ; C₃  =0.1 M

Number of moles of sodium citrate: n¹ = V₁*C₁
                                                                      = 0.0245*0.1 = 0.00245 (mol)

Equation:   3 Sodium hydroxide + 1citric acid  1 sodium citrate + 3 water
                0.0735 moles <-------- 0.0245 moles <------- 0.0245 moles     ---------

Until here, you know the number of moles of Sodium hydroxide and number of moles of citric acid. It's easy to calculate the volumes of each solution need

Sodium hydroxide: V₂ = n₂/C₂  = 0.735 dm³ = 735 cm³

Citric acid: V₃ = n₃/C₃  = 0.245 dm³      = 245 cm³

If you want to use the sodium hydroxide 1M and citric acid 1M, the step-by-step calculation is the same. You just have to change the numerical values.