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Chapter 14 Problem Set Key: Preparing Laboratory Solutions That
Contain More Than One Solute
1. This question concerns the following multi-component solution:
Solution A
1 M NaOH (FW = 40)
10% SDS
A.
Suppose that you were going to make 500 mL of Solution A
from pure NaOH and SDS. Determine how much of each
component you will need:
Amount NaOH required: ___20g___
Amount SDS required: ____50g_____
B.
Suppose that you are going to make 250 mL of Solution A
using a 10 M NaOH stock solution and a 20% SDS stock
solution. How much of each stock solution will you need to
use?
Volume 10 M NaOH required: ___25 mL____
Volume 20% SDS required:
___125 mL____
2. This question concerns the following multi-component solution:
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TES
100 mM Tris
10 mM EDTA
1% SDS
You are going to make up 350 mL of TES from the following stock
solutions: 1.5 M Tris, 0.5 M EDTA, and 20% SDS. Write a protocol
for how you will prepare this solution:
Mix together:
23.33 mL of 1.5 M Tris
7 mL of 0.5 M EDTA
17.5 mL of 20% SDS
and add enough water to make a final volume of 350 mL.
3. This question concerns the following multi-component solution:
10X ligation buffer
600 mM Tris, pH 7.6
100 mM MgCl2
70 mM DTT
If you take 150 uL of 10X ligation buffer and add 1350 uL of water,
what is the concentration of each of the components following
dilution?
Concentration of Tris =
__60 mM___
Concentration of MgCl2 =
___10 mM_____
Concentration of DTT =
___7mM_____
4. This question concerns the following multi-component solution recipe:
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To make 1 L of Solution X:
Add:
5 mL
10 mL
25 mL
1 M MgCl2
0.4% thymidine
20% glucose
Mix, and add enough water to bring the final volume to 1 L.
What are the final concentrations of each component in Solution X?
Concentration of MgCl2 =
____0.005 M____
Concentration of thymidine =
____0.004%___
Concentration of glucose =
___0.5%_____