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Bess [88]
3 years ago
7

Classify each as a physical or chemical change.

Chemistry
1 answer:
mars1129 [50]3 years ago
5 0

Answer:

a) When limestone is heated in a kiln, the calcium carbonate breaks down into calcium oxide and carbon dioxide. This type of reaction is called thermal decomposition. The process is called calcining. ... Slaked lime is used to reduce the acidity of the soil, which helps increase its fertility.

b) Mechanical digestion occurs in the mouth, stomach, and small intestine. Food is chemically changed indigestion when new, smaller substances are formed. These chemical changes are examples of chemical digestion. Chemical digestion begins in the mouth when enzymes in saliva begin to break down carbohydrates.

c)  Copper is a ductile metal. This means that it can easily be shaped into pipes and drawn into wires. Copper pipes are lightweight because they can have thin walls. They don't corrode and they can be bent to fit around corners.

d)  Ripening of fruits is a chemical change. During ripening the pigment present in the skin of the fruit changes and this can not be reversed back. it is a chemical change as once a fruit ripens it cannot turn raw again.

e)  Ice is a unique substance because it is solid-state — ice — is less dense than its liquid state. Because of this property, ice floats in water. Physical properties are characteristics of a substance. They do not change. Physical properties include colour, smell, freezing/melting point, and density.

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Gemiola [76]
<span>Sugar's carbon molecules can be arranged in a straight chain, a branched chain, or a ring.</span>
3 0
3 years ago
What is the change in atomic number when an atom emits a beta particle?
salantis [7]

When an atom emits a beta particle from the nucleus, the nucleus only has one more proton and one less neutron and this will make the atomic mass number remains unchanged while the atomic number increases by 1.

<span>I hope this answer helps you!</span>

4 0
3 years ago
Read 2 more answers
An alloy is made up of more than one type of what?
pychu [463]
More than one type of metallic elements.
4 0
3 years ago
Calculate the ph of sweater which has a hydrogen ion concentration of 1 times 10 to the power of 8
telo118 [61]

Answer:

The pH of the sweater containing Hydrogen ion concentration

[H^{+}]=1\times 10^{-8} is

<u>8</u>

<u></u>

Explanation:

pH = It is the negative logarithm of activity (concentration) of hydrogen ions.

pH = -log([H+])

Now, In the question the concentration of [H+] ions is :

[H^{+}]=1\times 10^{-8}

pH = -log(1\times 10^{-8})

use the relation:

log(10^{-a})=a

pH= -(-8)

pH = 8

Note : <em><u> 1 times 10 to the power of 8 must be" 1 times 10 to the power of -8"</u></em>

If the concentration is

[H^{+}]=1\times 10^{8}

Then pH = -8 , which is not possible . So in that  case the pH calculation is by other method

5 0
3 years ago
Calculate the solubility of benzene in water at 25 c in ppm. the required henry's law constant is 5.6 bar/mol/kg and benzene's s
kap26 [50]

The relationship between pressure and solubility of the gas is given by Henry's law as:

S_g = kP_g

where,

S_g is the solubility of the gas.

k is proportionality constant i.e. Henry's constant.

P_g is pressure of the gas.

k = 5.6 bar/mol/kg (given)

P_g = 0.13 bar (given)

Substituting the values,

S_g = 5.6 bar/mol/kg\times 0.13 bar = 0.728 mole/kg

To convert mole/kg to g/kg:

Molar mass of benzene, C_6H_6 = 6\times 12+6\times 1 = 78 g/mol

0.728\times 78 = 56.784 g/kg

Now for converting into ppm:

Since, 1 ppm = 0.001 g/kg

So, 56.784\times 1000 = 56784 ppm.

Hence, the solubility of benzene in water at 25^{o} C in ppm is 56784 ppm.


7 0
3 years ago
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