Recent content by TheShiny

That's what I'm not too certain about. Is it the water that the initial solution is diluted with?

Sorry if I caused confusion, that is the question verbatim. What I don't fully understand is how the "sodium salt of a weak acid" affects the calculations that I need to do. Because, based on inspection, comparing concentrations as well as pH and pka, I think that the volume to add should be...

Acid: HA and C. Base: A- ?

The acid is 0.208 M HCl. I calculated that I should add 24.4mL.

Okay, so I've just had a go and I get: [A-]/[HA] = 0.92896 Base: 50mL * 0.236M = 11.8mM (11.8-x)/x = 0.92896 => x = 6.11727 6.11727/0.208 = 24.4mL

Thank you for your responses. If I had the question "Prepare a buffer solution of pH 3.924 from 50 mL of 0.236 M solution of a sodium salt of a weak acid, Na+A- where the pka of the weak acid, HA, is 3.956. What volume, in mL, of 0.208 M HCl would need to be added?" Would I use the same method...

Homework Statement Prepare a buffer solution of pH 3.746 from 25 mL of 0.244 M weak acid with pka 3.54 What volume, in mL, of 0.275 M NaOH would need to be added? I think that I have the answer but I am not sure, could you look over the working to check? Also, would you do this differently...

If the particle (the car) is slowing down it would have negative acceleration. So, to go from acceleration to deceleration multiply by -1. Therefore the deceleration would be -1 * -0.625 = 0.625 Is that why the answer is positive or have I misunderstood?

Homework Statement "A car is approaching traffic lights. The car is traveling with speed 10ms-1. The driver applies the brakes to the car and the car comes to rest with constant deceleration in 16s. Modelling the car as a particle, find the deceleration of the car." Homework Equations v...