#1. How many mols NaCl do you want? That's mols = M x L = ?
Then mols = grams/molar mass. You know mols and molar mass, solve for grams. To prepare the solution you place that many grams (the ? calculated above) in a 250 mL volumetric flask, add some water, swirl until all of the NaCl is dissolved, add water to the mark on the flask, stopper, mix thoroughly.
#2. Use the dilution formula of
L1 x M1 = L2 x M2
1.25L x 0.025M = L2 x 5.00 M. Solve for L2.
#3. Frankly, I don't think there is any advantage to adding NaCl to rice or pasta when cooking it. The addition of NaCl to water to lower vapor pressure thereby raising the boiling point of water, requires too much NaCl to be significant. Cooks will tell you to add NaCl when cooking (as opposed to adding it after cooking) is to "cook in" the salt/flavor. You will need to sort all of this out from what you've been told in class.
Describe how you would prepare 250.0 mL of a 0.1500 M NaCl solution given that the NaCl is supplied as a solid.
Describe how you would prepare 1.25 L of a 0.025 M sucrose solution from a stock solution with concentration of 5.00 M.
What is the benefit of adding salt to water when cooking rice or pasta? Explain your answer by discussing changes to vapour pressure.
4 answers
2.160692 x10 7 atm Is this the correct answer?
I meant
#1 0.00064168g/mol?
#2 0.006g/mol?
#1 0.00064168g/mol?
#2 0.006g/mol?
Q#2.use the formula Mi x Vi=Mf x Vf
0.025 x 1.25= 5 Vf.
once the final volume's been found,transfer the solution of that volume to an empty conical flask.then add distilled water to the required volume(in ths case,up to 1.25L or 1.25 cubic dm).
Shake the conical flask to ensure thorough mixing of the molecules
0.025 x 1.25= 5 Vf.
once the final volume's been found,transfer the solution of that volume to an empty conical flask.then add distilled water to the required volume(in ths case,up to 1.25L or 1.25 cubic dm).
Shake the conical flask to ensure thorough mixing of the molecules
0 answers