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3 years ago

what does the law of conservation of energy state? explain.please help quickly:(((( ill give u brainliest please!!

Chemistry

1 answer:

zaharov [31]3 years ago

8 0

Answer:

Energy is not created or destroyed but merely changes forms, going from potential to kinetic to thermal energy. This version of the conservation-of-energy principle, expressed in its most general form, is the first law of thermodynamics.

Explanation:

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Which planet in the solar system is least dense

ella [17]

Answer:

Saturn

Explanation:

4 0

3 years ago

(I)how many atoms are present in 7g of lithium?

ICE Princess25 [194]

Answer :

(i) The number of atoms present in 7 g of lithium are, $6.07\times 10^{23}$

(ii) The number of atoms present in 7 g of lithium are, $1.204\times 10^{24}$

(iii) The number of moles of $F_2$ is, 1 mole

The number of moles of $CO_2$ is, 0.5 mole

The number of moles of $OH^-$ is, 1 mole

Explanation :

Part (i) :

First we have to calculate the moles of lithium.

$\text{Moles of }Li=\frac{\text{Mass of }Li}{\text{Molar mass of }Li}$

Molar mass of Li = 6.94 g/mole

$\text{Moles of }Li=\frac{7g}{6.94g/mol}=1.008mole$

Now we have to calculate the number of atoms present.

As, 1 mole of lithium contains $6.022\times 10^{23}$ number of atoms

So, 1.008 mole of lithium contains $1.008\times 6.022\times 10^{23}=6.07\times 10^{23}$ number of atoms

Thus, the number of atoms present in 7 g of lithium are, $6.07\times 10^{23}$

Part (ii) :

First we have to calculate the moles of carbon.

$\text{Moles of }C=\frac{\text{Mass of }C}{\text{Molar mass of }C}$

Molar mass of C = 12 g/mole

$\text{Moles of }C=\frac{24g}{12g/mol}=2mole$

Now we have to calculate the number of atoms present.

As, 1 mole of carbon contains $6.022\times 10^{23}$ number of atoms

So, 2 mole of carbon contains $2\times 6.022\times 10^{23}=1.204\times 10^{24}$ number of atoms

Thus, the number of atoms present in 7 g of lithium are, $1.204\times 10^{24}$

Part (iii) :

To calculate the moles of $F_2$ :

$\text{Moles of }F_2=\frac{\text{Mass of }F_2}{\text{Molar mass of }F_2}$

Molar mass of $F_2$ = 38 g/mole

$\text{Moles of }F_2=\frac{19g}{19g/mol}=1mole$

Thus, the number of moles of $F_2$ is, 1 mole

To calculate the moles of $CO_2$ :

$\text{Moles of }CO_2=\frac{\text{Mass of }CO_2}{\text{Molar mass of }CO_2}$

Molar mass of $CO_2$ = 44 g/mole

$\text{Moles of }CO_2=\frac{22g}{44g/mol}=0.5mole$

Thus, the number of moles of $CO_2$ is, 0.5 mole

To calculate the moles of $OH^-$ ions :

$\text{Moles of }OH^-=\frac{\text{Mass of }OH^-}{\text{Molar mass of }OH^-}$

Molar mass of $OH^-$ = 17 g/mole

$\text{Moles of }OH^-=\frac{17g}{17g/mol}=1mole$

Thus, the number of moles of $OH^-$ is, 1 mole

4 0

3 years ago

in the chemical equation HCI+CaCO3 which element cannot be apart of the products a carbon b chlorine c nitrogen d oxygen

FromTheMoon [43]

Answer:

Nitrogen

Explanation:

The element nitrogen cannot be a product in the given reaction.

The reaction is;

HCl + CaCO₃

According to the law of conservation of matter, "matter is neither created nor destroyed in the cause of a chemical reaction".

The law suggests that, in a chemical reaction, we end up with the same species we started with. Although due to rearrangement of bonds, new compounds can form;

Starting atoms

These species will also be found in the product.

5 0

3 years ago

Fossils of the Dorudon, an aquatic mammal that lived over 40 million years ago, show a whale-like animal that had small, underde

irina [24]

Answer:

They prove that all animals evolved from a single ancestor

3 0

3 years ago

Consider the following reaction:

vfiekz [6]

Answer:

Kc = 4.76

Explanation:

To find the concentrations of CO and H₂ at equilibrium, you have to set up an ICE (Initial, Change, Equilibrium) table.

CO (g) + 2H₂(g) ⇌ CH₃OH (g)

I 0.32 M 0.53 M 0

C -x -2x +x

E 0.32-x 0.53-2x 0.16 M

Since you know the concentration of CH₃OH at equilibrium, it would be equal to x since 0 + x = 0.16. So,

[CH₃OH] = 0.16 M

[CO] = 0.32 - 0. 16 = 0.16 M

[H₂] = 0.53 - 2(0.16) = 0.21 M

Now that you have all the concentrations at equilibrium, you can calculate the equilibrium constant.

Kc = products ÷ reactants

= [CH₃OH] ÷ [CO][H₂]²

= 0.16 ÷ (0.16)(0.21)

Kc = 4.76

The equilibrium constant at this temperature is 4.76.

Hope this helps.

3 0

3 years ago