All categories

2 years ago

Which of these is an example of a chemical change?

Chemistry

1 answer:

Elena-2011 [213]2 years ago

3 0

Answer:

D. Burning a peice of wood

Explanation:

Because when you burn wood a chemical reaction happenes between the flames and the wood making the wood into ashes.

Hope this helps you :)

You might be interested in

Is it possible to decrease resistance of the wire without changing the material it's made out of?

loris [4]

Yes, it is possible to decrease the resistance of a wire without changing the material it made out of. This is because, there are many factors which affect the resistance of a wire. These factors can be manipulated to change the resistance of the wire. The factors include: cross sectional area of the wire, length of the wire, temperature and the material of the wire. The other three factors can be manipulated to change the resistance of the wire without changing the material of the wire.

3 0

2 years ago

What methods do scientists use to determine if a change was physical or chemical?

Bess [88]

A physical change will not change the chemical make-up of the material. the change will not produce a new substance.

a chemical change will have a reaction that produces heat, light, a change in color, releases a gas, or rust

5 0

3 years ago

the mass by mass percentage of a solution is 20%. find the mass of the solute dissolved in 500g of solution

GuDViN [60]

Answer:

$m_{solute}=100g$

Explanation:

Hello,

In this case, by considering the mathematical definition of by mass percentage of a solute as shown below:

$\%m/m=\frac{m_{solute}}{m_{solution}}*100\%$

We are able to compute the mass of the solute in a 20% solution having 500 g of solution as follows:

$m_{solute}=\frac{m_{solution}*\%m/m}{100\%} =\frac{500g*20\%}{100\%}\\ \\m_{solute}=100g$

Best regards.

6 0

3 years ago

Which liquid has the highest vapor pressure at 75°C?

Temka [501]

Answer:

1) Ethanol

Explanation:

If we will have interactions we will need more energy to break them in order to go from liquid to gas. If we need more energy, therefore, the temperature will be higher.

In this case, we can discard the propanone because this molecule don't have the ability to form hydrogen bonds. (Let's remember that to have hydrogen bonds we need to have a hydrogen bond to a heteroatom, O, N, P or S).

Then we have to analyze the hydrogen bonds formed in the other molecules. For ethanol, we will have only 1 hydrogen bond. For water and ethanoic acid, we will have 2 hydrogen bonds, therefore, we can discard the ethanol.

For ethanoic acid, we have 2 intramolecular hydrogen bonds. For water we have 2 intermolecular hydrogen bonds, therefore, the strongest interaction will be in the ethanoic acid.

The closer boiling point to the 75ºC is the ethanol (boiling point of 78.8 ºC) therefore these molecules would have enough energy to break the hydrogen bonds and to past from liquid to gas.

4 0

2 years ago

Why is making a peanut pretzel and cereal mixture

guajiro [1.7K]

It is two or more objects and different things that can be removed from each other.

7 0

2 years ago