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3 years ago

Where the values come from?

Chemistry

1 answer:

Scrat [10]3 years ago

5 0

Answer:

To find the average atomic mass, you take a certain number of atoms, find the total mass of each isotope, and then divide the total mass of all the atoms by the total number of atoms. Assume that you have, say, 10 000 atoms of carbon

Explanation:

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If I use the dropper to add 10 mL of drink mix to 50 mL of water, what is the

Yuliya22 [10]

Answer:

16.7%

Explanation:

From the question given above, the following data were obtained:

Volume of drink mix = 10 mL

Volume of water = 50 mL

Percentage of drink mix =?

Next, we shall determine the total volume of the solution. This can be obtained as follow:

Volume of drink mix = 10 mL

Volume of water = 50 mL

Total volume of solution =?

Total volume of solution = (Volume of drink mix) + (Volume of water)

Total volume of solution = 10 + 50

Total volume of solution = 60 mL

Finally, we shall determine the percentage of the drink mix in the solution. This can be obtained as follow:

Volume of drink mix = 10 mL

Total volume of solution = 60 mL

Percentage of drink mix =?

Percentage of drink mix = Vol. of drink mix / total volume × 100

Percentage of drink mix = 10/60 × 100

Percentage of drink mix = 16.7%

4 0

3 years ago

Wrong answers only!<br><br><br> What color is an orange?

Anastaziya [24]

Answer:

Blue

Explanation:

5 0

2 years ago

Read 2 more answers

The number of grams per mole of something is also known as_______

Sergeeva-Olga [200]

Answer:

Molar mass

Explanation:

This is a counting unit which represents the mass in grams of a substance that make up one mole of the substance. This mass is calculated as follows:

Molar mass = Mass/ Number of moles

Units: grams/mol

5 0

3 years ago

Read 2 more answers

In the following overall chemical reaction, aluminum displaces chromium from chromium(III) oxide and forms aluminum oxide.

mafiozo [28]

Answer:

Change in enthalpy for the reaction is -536 kJ

Explanation:

Overall chemical reaction can be represented a summation of two given elementary steps with slight modification.
Take reaction (1a) and divide stoichiometric coefficients by 2
Take reverse reaction (2a) and divide stoichiometric coefficient by 2
Then add these two modified elementary steps to get overall chemical reaction
$\Delta H$ is an additive property. hence value of $\Delta H$ will be changed in accordance with modification

$2Al+\frac{3}{2}O_{2}\rightarrow Al_{2}O_{3}.....\Delta H_{1}=\frac{-3351.4}{2}kJ=-1675.7kJ$

$Cr_{2}O_{3}\rightarrow 2Cr+\frac{3}{2}O_{2}....\Delta H_{2}=\frac{2279.4}{2}kJ=1139.7kJ$

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$2Al+Cr_{2}O_{3}\rightarrow 2Cr+Al_{2}O_{3}....\Delta H=\Delta H_{1}+\Delta H_{2}=-1675.7+1139.7kJ=-536kJ$

6 0

3 years ago

For a particular isomer of C8H18, the combustion reaction produces 5104.1 kJ of heat per mole of C8H18(g) consumed, under standa

Vladimir79 [104]

Answer:

Explanation:

Hello,

Considering the chemical reaction, the enthalpy of reaction is given by:

ΔH°rxn=ΔfHCO2+ΔfHH2O-ΔfHC8H18

(ΔfHO2=0)

Taking into account that the reaction produces energy, ΔH°rxn is negative. No, solving for ΔfHC8H18:

ΔfHC8H18=-ΔH°rxn+8*ΔfHCO2+9*ΔfHH2O

ΔfHC8H18=-(-5104.1 kJ/mol)+9*(-292.74kJ/mol)+8*(-393.5 kJ/mol)

ΔfHC8H18=-678.56 kJ/mol

Best regards.

3 0

3 years ago