Sem Solutions Flashcards
Increasing the pressure on a gas will _____ the volume
Decrease
The melting point of water is ____ degrees C
0
What is a good example of a colloid ?
A. Vegetable oil
B. Mayonnaise
C. Butter
D. Sugar in water
Mayonnaise
You leave a mixture sitting on a table. Over time, it separates due to gravity. The mixture is likely a ….
A. Solution
B. Nonpolar
C. Suspension
D. Colloid
A
If you burn a piece of paper, that would be considered a(n) ______ reaction
Exothermic
What does 2 M NaCl mean?
2 moles NaCl per liter
In ocean water (salt and water), what term best describes the SALT?
A. Solution
B. Saturated
C. Solute
D. Solvent
C
If you mix chemicals together and an ENDOTHERMIC reaction takes place, the container will feel …
Colder
Oil is a nonpolar compound. Which will dissolve in oil?
A. Water
B. Salt
C. Polar compound
D. Nonpolar compound
D
A 50g sample contains 0.004g of calcium. Calculate the parts per million.
Answer: 80 ppm
Work:
Solute/ solution • 1,000,0000
0.004/50= 0.00008 • 1,000,000 = 80
What is the molarity of a 250mL solution containing 30g of NaCl?
Answer: 2.04 M NaCl
Work:
1mol 30gNaCl • --------- = 0.51
58.45g NaCl
250/1000 = 0.25
0.51 mol M = ---------- = 2.04 M NaCl
0.25 L
A 20 liter balloon at 100 kpa and 100^C was changed to 110 kpa and 50^C. What is the new volume ?
Answer: 15.74 L
Work:
100 | 20 | 373
110 | | 323
(20)(100)(323) = 646,000
646,000/ 110 = 5872.727 / 373 = 15.74
How much energy is needed to change 100g of water from 20^C to 100^C (SpHt of water = 4.18j/g^C)
E = 33, 440J
How many grams of table salt are needed to dissolve in 2 liters of water to make a 3 M solution?
Answer: 350.7gNaCl
Work:
X
(2) 3MNaCl = ------- (2)
2L
X= 6 mol
58.45g 6mol • ---------- = 350.7 g NaCl
1 mol
