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3 years ago

Which of the following is not an indication of a chemical change?

Chemistry

1 answer:

Sauron [17]3 years ago

5 0

Answer:

C. precipitate formation.

Explanation:

options C is correct answer.

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When an object falls toward the ground due to gravity, what type of energy becomes kinetic energy?

Goshia [24]

OPTION C

<h2>POTENTIAL ENERGY </h2>

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6 0

3 years ago

Read 2 more answers

Typical "hard" water contains about 2.0 x 10–3 mol of Ca2+ per liter. Calculate the maximum concentration of fluoride ion that c

malfutka [58]

Answer:

$[F^-]_{max}=4x10{-3}\frac{molF^-}{L}$

Explanation:

Hello,

In this case, for the described situation, we infer that calcium reacts with fluoride ions to yield insoluble calcium fluoride as shown below:

$Ca^{+2}(aq)+2F^-(aq)\rightleftharpoons CaF_2(s)$

Which is typically an equilibrium reaction, since calcium fluoride is able to come back to the ions. In such a way, since the maximum amount is computed via stoichiometry, we can see a 1:2 mole ratio between the ions, therefore, the required maximum amount of fluoride ions in the "hard" water (assuming no other ions) turns out:

$[F^-]_{max}=2.0x10^{-3}\frac{molCa^{2+}}{L}*\frac{2molF^-}{1molCa^{2+}} \\$

$[F^-]_{max}=4x10{-3}\frac{molF^-}{L}$

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8 0

3 years ago

The plant chemical which absorbs sunlight and helps make cell food is

UkoKoshka [18]

Answer:

chlorophyll

Explanation:

8 0

3 years ago

A train that is accelerating at 5m/s² down the tracks and crashes into a car. If the train weighs 20,000kg, how much force does

iragen [17]

Answer:

100,000 N

Explanation:

Force, F = mass, m × acceleration, a

⇒F = ma

m= 20, 000kg

a = 5m/s²

∴ F = 5 × 20,000 = 100,000N

3 0

3 years ago

What is the total number of calories of heat energy absorbed when 10 grams of water is vaporized at its normal boiling point

Darya [45]

<u>Answer:</u> The amount of energy absorbed by water is 5390 Calories

<u>Explanation:</u>

To calculate the amount of heat absorbed at normal boiling point, we use the equation:

$q=m\times L_{vap}$

where,

q = amount of heat absorbed = ?

m = mass of water = 10 grams

$L_{vap}$ = latent heat of vaporization = 539 Cal/g

Putting values in above equation, we get:

$q=10g\times 539Cal/g=5390Cal$

Hence, the amount of energy absorbed by water is 5390 Calories

6 0

3 years ago