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3 years ago

6 Calculate the number of molecules in 8 g of oxygen.

Chemistry

1 answer:

Mariana [72]3 years ago

3 0

Answer:

If you mean the number of atoms in 8g of oxygen, it's 3.011 x 10^23 atoms.

Explanation:

Convert the grams to moles. 8 grams of oxygen is 0.5 moles. Then multiply the number of moles by Avogadro's number: 6.022 x 10^23.

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Calculate the energy, in joules, to heat two cubes (silver and copper), each with a volume of 10.0cm, from 15 C to 25 C

Julli [10]

Answer:

For Silver , The heat absorbed = 246.75 J

For Copper , The heat is = 343.42 J

Explanation:

The change in temperature is calculated by:

$\Delta T=T_{2}-T_{1}$

T2 = 25 C

T1 = 15 C

$\Delta T=25-15$

$\Delta T=10^{0}C$

The energy in Joules can be calculated using :

$q=mc\Delta T$

here , m = mass of the substance

c = the heat capacity

q = heat absorbed / released

We need to calculate the mass , In order to determine the value of "q".

Calculation for Silver :

The mass is calculated from the density of the element.

density of Silver = 10.5 g/ml (look at the table of density)

Volume of Cube = 10 cm^3 (given)

1 cm^3 = 1 mL

10 cm^3 = 10 mL

The mass can be calculated using the formula:

$mass = density\times Volume$

$mass = 10.5\times 10$

$mass = 105grams$

Insert the value of m , c, T in the equation.

for Silver the value of "c"= 0.235 J/gC (Look at the table)

$q=mc\Delta T$

$q=105\times 0.235\times 10$

$q=246.75J$

Calculation for Copper:

Again first calculate the mass of Copper.

Density of Copper = 8.92 g/ml

Volume = 10 mL

$mass = density\times Volume$

$mass = 8.92\times 10$

$mass = 89.2grams$

Insert the value of m , c, T in the equation.

for Silver the value of "c"= 0.385 J/gC (Look at the table)

$q=mc\Delta T$

$q=89.2\times 0.385\times 10$

$q=343.42J$

8 0

3 years ago

4. If they..................me a question d have answered it.(ask/asked/had asked)

LekaFEV [45]

Answer:

had asked

Explanation:

If they had asked me a question, I would have answered it.

5 0

3 years ago

Read 2 more answers

Which organism has the following characteristics: heterotrophic, eukaryotic,

Soloha48 [4]

This organism is Fungi, which can either be unicellular or multicellular, and has the only cell wall made of chitin out of the four.

6 0

2 years ago

What defining feature makes a material an insulator?

kompoz [17]

A defining feature of a material that is a good insulator would be its ability to stop or cancel an electric charge of another material. This happens because the molecules in the material are stable and there are no free electrons that would allow the charges to flow.

3 0

3 years ago

Find the % composition for each element in Zn(CIO3)2

bezimeni [28]

Zn = 28.15%

Cl = 30.53%

O = 41.32%

<h3>Further explanation</h3>

Given

Zn(CIO3)2 compound

Required

The % composition

Solution

Ar Zn = 65.38

Ar Cl = 35,453

Ar O = 15,999

MW Zn(CIO3)2 = 232.3

Zn = 65,38/232.3 x 100% = 28.15%

Cl = (2 x 35.453) / 232.3 x 100% = 30.53%

O = (6 x 15.999) / 232.3 x 100% = 41.32%

7 0

2 years ago