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3 years ago

Why does a penny become warmer when it is struck with a hammer?

1 answer:

8 0

Because the penny absorbs the kinetic energy from the impact and releases it back into the environment as heat since the energy cannot be stored as potential energy.

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Chemistry table practice

Sonbull [250]

Explanation:

I don't understand your question....

thank you

5 0

3 years ago

If I know the number of protons an element has do I know what element it is ?

Stella [2.4K]

Answer:

Yes.

Explanation:

The atomic number is derived from the number of protons. For example: Radium has 88 protons and its atomic number is 88. Helium has 2 protons its atomic number is 2. Sodium's atomic number is 11 it has 11 protons.

5 0

3 years ago

A 0.600 g sample of a compound of arsenic and oxygen was found to

ss7ja [257]

Answer:

The answer is C. As2O3

Explanation:

0.600 gr of Arsenic and Oxygen.

0.454 gr of Arsenic

So, 0.146 gr of Oxygen will be in the compound.

- First: The grams of each element must be divided by its atomic weight:

0.454 gr As / 74.92u As = 0.00606

0.146 gr O / 16u O = 0.009125

- Both results must be divided by the lowest number found:

0.00606 / 0.00606 = 1 As

0.009125 / 0.00606 = 1.5 O

- As one of the values is not an integer then both results are multiplied until both give an integer:

1 As * 2 = 2 As

1.5 O * 2 = 3 O

- Then the answer is given:

As2O3

5 0

3 years ago

What is the Celsius temperature of 1 mole of a gas that has an average kinetic energy of 3,866 joules?

BARSIC [14]

It is 73 degrees Celsius. You can find this on another site.

6 0

4 years ago

An imaginary planet was just discovered that has a similar environment to our planet Earth. All the chemistry is similar except

Lena [83]

Answer: $\Delta H_{rxn}=-4652$ kJ/mol

Explanation: In a reaction, a bond of a molecule can break or rearrange itself. When it happens, it absorb or release energy.

Bond Energy is the energy necessary to break or to make a particular bond, producing gaseous fragments at atmospheric temperature. This type of energy can be used to show how stable a compound is or how easy a bond can break.

Enthalpy of Reaction is the energy absorption or release at a constant temperature resulting from a chemical reaction.

To calculate the Enthalpy using bond energy, you have:

1) Write the balanced equation with all the all the reactants and products in gaseous form:

$C_{5}H_{12}_{(g)}+8O_{2}_{(g)}$ ⇒ $5CO_{2}_{(g)}+6H_{2}O_{(g)}$

2) Count each bond of each molecule from both sides, including double or triple bonding, if they exists:

Reactants:

$C_{5}H_{12}$ : 12 C-H

4 C-C

O₂ : 1 O=O

Products:

CO₂ : 2 C=O

H₂O : 2 H-O

3) From the balanced reaction, we there are 8 moles of oxygen gas, 5 moles of carbon dioxide and 6 moles of water, which has to be included when adding each side.

$\Sigma H_{reactants}=$ 12.257 + 4.370 + 8.490 = 8484

$\Sigma H_{products}=$ 5.2.740 + 6.2.478 = 13136

4) Calculate Enthalpy of Reaction by:

$\Delta H_{rxn}= \Sigma H_{reactants}-\Sigma H_{products}$

$\Delta H_{rxn}=8484-13136$

$\Delta H_{rxn}=-4652$

The enthalpy of reaction for the combustion of 1 mole of pentane on a just discovered imaginary planet is an exothermic process of magnitude $\Delta H_{rxn}=$ - 4652kJ/mol

8 0

3 years ago