The unit cm3 is used to express

Express the concentration of a 0.0390 M aqueous solution of fluoride, F–, in mass percentage and in parts per million. Assume th

mart [117]

ppm = mg/L
or
Kg solution Mass % = Mass of Solute/Mass of solution

0.0390 M = x moles/1L
x = 0.0390 Moles of F-
0.0390 mol x 18.998403 g/mol = 0.7409 g

PPM:
1mg = 1000g
0.7409g = 740.9mg
740.9mg/1L = 740.9mg

Mass Percent:
density 1 g/mL
thus
1 g = 1 mL
thus 1 L = 1 kg
thus 1 L = 1000 g
so,
(0.7409 g/1000 g)*100
= 0.07409% (m/m)

4 0

3 years ago

1. How do you think shivering on a cold day helps maintain internal body conditiona?

quester [9]

Answer:

shivering is a natural bodily response, the body is trying to heat itself up by moving around.

7 0

3 years ago

Jill is studying the temperature output of an ammonium chloride hand warmer with a calorimeter. What change should she expect to

ANEK [815]

Answer:

The water will continue to heat up as the experiment progresses.

Explanation:

When a person's fingers are cold or has a muscles ache, one can use chemical hand warmers to heat them up. There are two types of chemical hand warmer products, and they all depend on exothermic chemical reactions to work.

However, ammonium chloride dissolution is endothermic but its crystalization is exothermic. When used as a hand warner with a calorimeter, it is found that the temperature of the water increases steadily due to the crystalization of the ammonium chloride. Hence the answer.

7 0

3 years ago

If you have 2.4L of SO2 gas (at STP) how many moles of sulfur dioxide do you have?

Andru [333]

Answer:

0.107 mole of SO2.

Explanation:

1 mole of a gas occupy 22.4 L at standard temperature and pressure (STP).

With the above information, we can simply calculate the number of mole of SO2 that will occupy 2.4 L at STP.

This can be obtained as follow:

22.4 L contains 1 mole of SO2.

Therefore, 2.4 L will contain = 2.4/22.4 = 0.107 mole of SO2.

Therefore, 0.107 mole of SO2 is present in 2.4 L at STP.

4 0

3 years ago

Is questions 1,2,3 right? If not what is the right answers and can someone give me the answer for question 4

Vadim26 [7]

your question: 

Is questions 1,2,3 right? If not what is the right answers and can someone give me the answer for question 4

answer: 

1. E

2. G

3. Correct - F

4. A

5. B

Hope this helps, have a great day! :)

5 0

3 years ago