What happens when water changes from a solid to a liquid to a vapor

What process transform solar energy into chemical energy?

DIA [1.3K]

Green plants transform solar energy to chemical energy (mostly of oxygen) through the process known as photosynthesis, and electrical energy can be converted to chemical energy and vice versa through electrochemical reactions.

8 0

3 years ago

A 5.000 g mixture contains strontium nitrate and potassium bromide. Excess lead(II) nitrate solution is added to precipitate out

scZoUnD [109]

Answer: The mass percent of potassium bromide in the mixture is 9.996%

Explanation:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ .....(1)

For lead (II) bromide:

Given mass of lead (II) bromide = 0.7822 g

Molar mass of lead (II) bromide = 367 g/mol

Putting values in equation 1, we get:

$\text{Moles of lead (II) bromide}=\frac{0.7822g}{367g/mol}=0.0021mol$

The chemical equation for the reaction of lead (II) nitrate and potassium bromide follows:

$2KBr+Pb(NO_3)_2\rightarrow PbBr_2+2KNO_3$

By Stoichiometry of the reaction:

1 mole of lead (II) bromide is produced from 2 moles of potassium bromide

So, 0.0021 moles of lead (II) bromide will be produced from = $\frac{2}{1}\times 0.0021=0.0042mol$ of potassium bromide

Now, calculating the mass of potassium bromide by using equation 1, we get:

Molar mass of KBr = 119 g/mol

Moles of KBr = 0.0042 moles

Putting values in equation 1, we get:

$0.0042mol=\frac{\text{Mass of KBr}}{119g/mol}\\\\\text{Mass of KBr}=0.4998g$

To calculate the percentage composition of KBr in the mixture, we use the equation:

$\%\text{ composition of KBr}=\frac{\text{Mass of KBr}}{\text{Mass of mixture}}\times 100$

Mass of mixture = 5.000 g

Mass of KBr = 0.4998 g

Putting values in above equation, we get:

$\%\text{ composition of KBr}=\frac{0.4998g}{5.000g}\times 100=9.996\%$

Hence, the percent by mass of KBr in the mixture is 9.996 %

5 0

3 years ago

Acid rain is composed mainly of the oxides of two elements. give either.

Nutka1998 [239]

The two elements that are responsible for acid rain are sulphur and nitrogen.

8 0

4 years ago

Why is acid important for digestion

Troyanec [42]

Answer:

activating digestive enzymes, and making ingested proteins unravel so that digestive enzymes break down the long chains of amino acids

5 0

3 years ago

Read 2 more answers

What’s the answer to this science problem?

Law Incorporation [45]

Answer:

The image is not accurate because

the heavier atoms are moving faster than the lighter ones

but the lighter ones must move faster than the heavier ones.

Explanation:

The image depicts the atoms of two different elements; atoms of lighter and heavier elements.

And the rate of diffusion (movement of atoms) of an element is inversely proportional to the square root of its molecular.

⇒ As the weight increases, the rate of diffusion (movement of atoms) decreases.

And as the weight decreases, the rate of diffusion (movement of atoms) increases.

so, heavier atoms move slowly compared to lighter atoms.

The image is not accurate because

the heavier atoms are moving faster than the lighter ones

but the lighter ones must move faster than the heavier ones.

5 0

3 years ago