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dezoksy [38]
3 years ago
14

A substance undergoes a change. Which of the following indicates that the change was a chemical change?

Chemistry
1 answer:
hoa [83]3 years ago
4 0
The answer is A. <span>The substance changed shape.

There you go!</span>
You might be interested in
How would a system in which both matter and energy are exchanged freely between the system and the surroundings be classified? (
Nata [24]

Answer:

An open system

Explanation:

An open system is a system in which both matter and energy are exchanged freely between the system and the surroundings.

An example is a pot of water boiling on the stove. The surroundings (the stove) can supply heat energy to the water and the water can escape into the atmosphere.

A <em>closed system</em> is a system in which energy but not matter is exchanged freely between the system and the surroundings.

An example is a pressure cooker on the stove. The surroundings (the stove) can supply heat energy to the food inside, but no matter can escape through the closed lid.

An <em>isolated system</em> is a system in which neither energy nor matter can be exchanged between the system and the surroundings.

An example is a thermos of hot soup. The cap prevents matter from escaping and the shiny interior reflects heat back into the soup.

8 0
3 years ago
What is the freezing point of an aqueous solution that boils at 105.0 ∘C? Express your answer using two significant figures.
konstantin123 [22]

Answer:

T°fussion of solution is -18°C

Explanation:

We have to involve two colligative properties to solve this. Let's imagine that the solute is non electrolytic, so i = 1

First of all, we apply boiling point elevation

ΔT = Kb . m . i

ΔT = Boiling T° of solution - Boiling T° of pure solvent

Kb =  ebuliloscopic constant

105°C - 100° = 0.512 °C kg/mol  . m . 1

5°C / 0.512 °C mol/kg = m

9.7 mol/kg = m

Now that we have the molality we can apply, the Freezing point depression.

ΔT = Kf . m . i

Kf =  cryoscopic constant

0° - (T°fussion of solution) = 1.86 °C/m  . 9.76 m . 1

- (1.86°C /m . 9.7 m) = T°fussion of solution

- 18°C = T°fussion of solution

5 0
3 years ago
Changing subscripts is one of the steps of balancing a chemical equation.<br> True or False
Lostsunrise [7]

Answer:

False

Explanation:

Changing the coefficients is one of the steps of balancing a chemical equation. Changing the subscript changes the compounds being used, while changing the coefficient changes the amount of each compound being used.

3 0
3 years ago
Read 2 more answers
Jimmy's Chemical reaction/ Recipe for making Grilled chese sandwiches is given below: 1 slice of cheese + 2 slices of bread = 1
Juli2301 [7.4K]

Answer:

See explanation

Explanation:

We have been told in the question that the equation of the reaction is; 1 slice of cheese + 2 slices of bread = 1 Grilled cheese sandwich ( mole ratio is, 1:2:1) .

Then the reagents are 10 slices of cheese 30 slices of bread. It then follows that 10 slices of cheese should be combined with 20 slices of bread according to the mole ratio.

However, we have 30 slices of bread and 10 slices of cheese so cheese is the limiting reactant while bread is the reactant in excess.

Yes, the number of glilled chese sandwishes he can make is decided by the limiting reactant because it gets used up most.

4 0
3 years ago
A chemist combines ethane and chlorine with the goal of producing chloroethane which other product could be reasonably expected
lesya692 [45]
<span>So when the chemist combines Ethane (CH3CH3) and Chlorine (Cl2) with the intention of producing Chloroethane (CH3CH2Cl), the other product that's formed in this reaction is 1,2-dichloroethane (ClCH2CH2Cl) also called as Ethylene dichloride with molecular weight of 98.954 g/mol. This is a colorless oily flammable substance that weighs heaver when vaporized.</span>
5 0
3 years ago
Read 2 more answers
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