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musickatia [10]

4 years ago

10

A student puts a glass of water in the freezer. Later, he notices ice forming on the surface of the water. Which property of wat

er best explains why ice forms on its surface?

1 answer:

Marina86 [1]4 years ago

4 0

Answer: since water is denser than the ice, the ice, floats to the top

Explanation:

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The burning of propane gas can be represented as a balanced chemical reaction as follows: C3H8(g)+5O2(g)→3CO2(g)+4H2O(g) Calcula

Snezhnost [94]

Answer: 20L of H2O

Explanation:

C3H8 + 5O2 → 3CO2 + 4H2O

Recall 1mole of a gas contains 22.4L at stp

5moles of O2 contains = 5 x 22.4 = 112L

4moles of H2O contains = 4 x 22.4 = 89.6L

From the equation,

112L of O2 produced 89.6L H2O

There for 25L of O2 will produce XL of H2O i.e

XL of H2O = (25 x 89.6)/112 = 20L

6 0

4 years ago

The atomic number of Oxygen is 8. Therefore, which of the following answers would correspond to what would be in the nucleus of

melomori [17]

Answer:

Its official chemical symbol is O, and its atomic number is 8, which means that an oxygen atom has eight protons in its nucleus. ... Oxygen is normally found as a

5 0

2 years ago

How do you prepare 500 ml of a 1.77M H2SO4 solution from an 18.0 M H2SO4 stock solution?

finlep [7]

Answer:

Molarity Problems Worksheet

M=nV n= # moles

V must be in liters (change if necessary)

1. What is the molarity of a 0.30 liter solution containing 0.50 moles of NaCl?

1.7M

2. Calculate the molarity of 0.289 moles of FeCl3 dissolved in 120 ml of solution?

2.41 M

3. If a 0.075 liter solution contains 0.0877 moles of CuCO4, what is the molarity?

1.2M

4. How many moles of NaCl are present in 600. ml a 1.55 M NaCl solution?

.930 moles

5. How many moles of H2SO4 are present in 1.63 liters of a 0.954 M solution?

1.56 molse

6. How many liters of solution are needed to make a 1.66 M solution containing 2.11 moles of KMnO4?

1.27 g

7. What volume of a 0.25 M solution can be made using 0.55 moles of Ca(OH)2?

2.2 L

For all of the problems below you will need to do a mole-mass conversion. Each problem will involve two steps.

8. What is the molarity in 650. ml of solution containing 63 grams of NaCl?

1.7 M

9. How many grams of Ca(OH)2 are needed to produce 500. ml of 1.66 M Ca(OH)2 solution?

61.5 g

10. What volume of a 0.88 M solution can be made using 130. grams of FeCl2?

1.2 L

Dilution Problems Worksheet

1. How do you prepare a 250.-ml of a 2.35 M HF dilution from a 15.0 M stock solution?

39.2 mL

2. If 455-ml of 6.0 M HNO3 is used to make a 2.5 L dilution, what is the molarity of the dilution?

1.1 M

3. If 65.5 ml of HCl stock solution is used to make 450.-ml of a 0.675 M HCl dilution, what is the molarity of the stock solution?

4.64 M

4. How do you prepare 500.-ml of a 1.77 M H2SO4 dilution from an 18.0 M H2SO4 stock solution?

Take 49.2-ml of 18.0 M H2SO4 stock solution and pour it into a 500-ml volumetric flask. Fill to the 500-ml line with distilled water to make 1.77M H2SO4 solution.

Extra Molarity Problems for Practice

1. How many moles of LiF would be required to produce a 2.5 M solution with a volume of 1.5 L?

3.75 M

2. How many moles of Sr(NO3)2 would be used in the preparation of 2.50 L of a 3.5 M solution?

8.75 M

3. What is the molarity of a 500-ml solution containing 249 g of KI?

3.00 M

4. How many grams of CaCl2 would be required to produce a 3.5 M solution with a volume of 2.0 L?

777 g

Explanation:

I've done this before

6 0

3 years ago

(07.07)What transformation has changed the parent function f(x) = log2 x to its new appearance shown in the graph below?(6 point

amid [387]

The answer is B. f ( x - 3 ) - 2

7 0

3 years ago

explain why it is a common laboratory procedure to heat analytical reagents and store them in a dessicated atmosphere (a sealed

Readme [11.4K]

Explanation:

Most reagent forms are going to absorb water from the air; they're called "hygroscopic". Water presence can have a drastic impact on the experiment being performed For fact, it increases the reagent's molecular weight, meaning that anything involving a very specific molarity (the amount of molecules in the final solution) will not function properly.

Heating will help to eliminate water, although some chemicals don't react well to heat, so it shouldn't be used for all. A dessicated environment is simply a means to "dry." That allows the reagent with little water in the air to attach with.

6 0

3 years ago