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2 years ago

How many atoms are in 15.6 grams of silicon?

Chemistry

1 answer:

Andreas93 [3]2 years ago

6 0

Answer:

3.34 x 1023 atoms

Explanation:

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What are the atomic and mass numbers for the periodic table of elements

chubhunter [2.5K]

there you go, hope that helps

8 0

2 years ago

At equilibrium, the concentrations in this system were found to be [N2]=[O2]=0.200 M and [NO]=0.400 M.

Kipish [7]

Answer:

The concentration in equilibrium of NO is 0,550M.

Explanation:

For the reaction:

N₂(g) + O₂(g) ⇄ 2NO

The equilibrium constant is defined as:

k = [NO]² / [N₂][O₂] (1)

Replacing for the concentrations in equilibrium:

k = (0,400M)² / (0,200M)(0,200M)

k = 4,000

If you add more NO until 0,700M, the equilibrium concentrations will be:

[NO] = 0,700M-2x

[N₂] = 0,200M+x

[O₂] = 0,200M+x

Replacing in (1)

4,000 = (0,700M-2x)² / (0,200M+x)²

4,000 = 4x²- 2,8x + 0,49 / x² + 0,4x + 0,04

4x² + 1,6x + 0,16 = 4x²- 2,8x + 0,49

4,4x = 0,33

x = 0,075M

That means that concentration in equilibrium of NO is:

[NO] = 0,700M - 2×0,075M = 0,550M

I hope it helps!

4 0

2 years ago

How much heat energy would be released if 78.1 g of water at 0.00 °c were converted to ice at −57.1 °c. give your answer as a po

kolezko [41]

To convert 78.1 g of water at 0° C to Ice at -57.1°C; we can do it in steps;
1. Water at 0°C to ice at 0°C
The heat of fusion of ice is 334 J/g;
Heat = 78.1 × 334 = 26085.4 Joules
2. Ice at 0°C to -57.1°C
Specific heat of ice is 2.108 J/g
Heat = 78.1 × 2.108 J/g = 164.6348 Joules
Thus the total heat energy released will be; 26085.4 + 164.6348
= 26250.0348 J or 26.250 kJ

3 0

2 years ago

Which statement describes vascular plants?

alexandr1967 [171]

Answer:

A vascular plant is any one of a number of plants with specialized vascular tissue. The two types of vascular tissue, xylem and phloem, are responsible for moving water, minerals, and the products of photosynthesis throughout the plant.

Explanation:

7 0

2 years ago

When benzene (c6h6) reacts with bromine (br2) bromobenzene(c6h5br) is obtained: c6h6 + br2 → c6h5br + hbr what is the theoretica

saveliy_v [14]

Answer A) : We have to calculate the number of moles of Benzene involved in the reaction,

30 g / 78 moles of benzene = 0.384 moles

For bromine it will be the same process,

65 g / 159.8 moles = 0.406 moles

By observing the reaction given above we can say that the reaction ratio of bromine and benzene is 1 : 1

We need to find the mass of bromobenzene,

which should be, 6(12) + 5 (1)+ 79.90 = 156.9 g/mol

So, the mass of bromobenzene will be 156.9 g/mol X 0.3846 mol = 60.343 g

Hence the theoretical yield will be 60.34 g

Answer B) : To calculate the actual yield we have to divide it with theoretical yield.

(56.7g / 60.343 g ) X100% = 93.96 %

Here, we can say that we got 93.96 % of actual yield.

As we know it is impossible to get 100% yield in any reaction.

3 0

2 years ago