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2 years ago

BRAINLIESTTT ASAP!!!

Chemistry

2 answers:

Stels [109]2 years ago

8 0

While I am not the brainliest I can certainly answer.

This was a chemical change because the chemical components were changed, a big giveaway to this was the fizzing, however the temperature rising was also another giveaway.

Vladimir79 [104]2 years ago

4 0

Explanation:

A physical change is the change that does not bring any difference in the chemical properties of a substance.

For example, change in shape, size, state, mass, density etc are all physical changes.

On the other hand, a chemical change is define as the one which brings difference in chemical composition of a substance.

For example, yeast granules were added to hydrogen peroxide then fizzing and bubbling took place. This means that a chemical reaction has taken place due to which a gas is liberating out of the solution.

Also, heat is liberating due to which temperature has began to rise.

Thus, we can conclude that based on the given observation a chemical change has taken place.

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5. You have 100 kg of gas of the following composition: CH4 - 30% H2 - 10% N2 - 60% What is the average molecular weight of this

Lorico [155]

Answer:

21.8 g/mol

Explanation:

Molecular weight of CH4 = 16g/mol

H2 = 2g/mol

N2 = 28g/mol

(16*30 + 2*10 + 28*60)/100

=2180/100

=21.8g/mol

6 0

1 year ago

2 attempts left select the single best answer. The radii of the lithium and magnesium ions are 76 pm and 72 pm, respectively. Wh

Lina20 [59]

The ionic character of any compound depend on the lattice energy as well as the electronegativity of element present in that compound.

More would be the lattice energy more would be ionic nature of that compound.

The lattice energy of any compound is inversely proportional to the ionic radii cation and anion.

In given case the ionic radii of oxide in both oxides would be equal therefore the lattice energy only depend on the ionic radii of cation.

$Lattice energy (U) = \frac{1}{Ionic radii}$

As the radii of Magnesium less then radii of lithium therefore lattice energy of Magnesium oxide would be more than lithium oxide.

Hence, MgO would be more ionic in nature than $Li_{2}O$

8 0

2 years ago

Question 2: Phase Changes (14 points) a. Rewrite each of the following equations for phase changes, to include the heat required

lilavasa [31]

Explanation:

(i) The equilibrium reaction equation will be as follows.

$H_{2}O(l) \rightleftharpoons H_{2}O(s)$

A reaction in which there will be absorption of heat energy is known as endothermic reaction.

A reaction in which there will be release of heat energy is known as exothermic reaction.

As liquid state of water is changing into solid state. So, it means that molecules of water came close to each other. Hence, there will be release of heat this means that reaction is exothermic in nature.

Hence, phase change from liquid to solid will be exothermic in nature.

Latent heat of fusion is defined as the amount of energy necessary to convert 1 gram of a solid into liquid state at its melting point.

So, when solid state of water changes into liquid state then it means energy is absorbed by the molecules of ice due to which they have gained kinetic energy. Hence, they moved away from each other leading to formation of liquid state of water.

Latent heat of freezing of liquid water is 334 J/g.

Specific heat of liquid water is 4.186 $J/g ^{o}C$

Specific heat of steam is 1.996 $kJ/kg/^{o}K$

Specific heat of ice is 2.1 $kJ/kg/^{o}K$

(ii) The equilibrium reaction equation will be as follows.

$H_{2}O(l) \rightleftharpoons H_{2}O(g)$

As liquid state of water is changing into gaseous or vapor state. So, it means molecules of liquid water has gained kinetic energy hence, they colloid more rapidly with each other.

As a result, heat will be absorbed by the liquid state of water. Hence, heat will be absorbed. Therefore, phase change from liquid to gas will be endothermic in nature.

Whereas when gaseous state of water will change into liquid state then heat will be released during this process of condensation. As a result, in that case reaction will be exothermic in nature.

5 0

2 years ago

The atmosphere supports a column of mercury that is 748 mm in height. What is atmospheric pressure in torr? Convert this pressur

gulaghasi [49]

Answer:

748 torr

Explanation:

mmHg and torr are equivalent so, you'll have 748 torr.

7 0

1 year ago

Complete the reaction, which is part of the electron transport chain. The abbreviation Q represents coenzyme Q. Use the appropri

fredd [130]

Answer:

x = 2+

Explanation:

1) FADH2 + Q => FAD + QH2

Since H is added to Q

=> Reactant reduced is Q

(2) Balancing charges on both sides of the equation gives:

QH2 + 2 cyt c(Fe3+) => Q + 2 cyt c(Fe2+) + 2 H+

Thus x = 2+

7 0

2 years ago