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Ugo [173]
3 years ago
7

a chemist is studying an unknown substance he can break it into its elemental only by using chemical means.Based on this observa

tion, how should the unknown substance be classified
Chemistry
1 answer:
Vanyuwa [196]3 years ago
4 0

Answer:

Compound

Explanation:

We want to know if it's a compound or a mixture.

An example of a mixture is salt water: you can heat it hot enough to boil off the water, leaving only the salt. This is a physical change, which is how you know it's a mixture.

Something like gold is a compound: if you heat it, or hit it, you'll still only have gold. You can only break it down by chemical means, which is how you know it's a compound.

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At equilibrium the reactant and product concentrations are constant because a change in one direction is balanced by a change in
Anna [14]

Answer: a. The concentrations of the reactants and products have reached constant values

Explanation:

The reactions which do not go on completion and in which the reactant forms product and the products goes back to the reactants simultaneously are known as equilibrium reactions.  For a chemical equilibrium reaction, equilibrium state is achieved when the rate of forward reaction becomes equal to rate of the backward reaction.

Equilibrium state is the state when reactants and products are present but the concentrations does not change with time and are constant.

Equilibrium constant is defined as the ratio of concentration of products to the concentration of reactants each raised to the power their stoichiometric ratios. It is expressed as K_{eq}

K is the constant of a certain reaction when it is in equilibrium, while Q is the quotient of activities of products and reactants at any stage other than equilibrium of a reaction.

For a equilibrium reaction,

A\rightleftharpoons B

K_{eq}=\frac{[B]}{[A]}

Thus the correct answer is the concentrations of the reactants and products have reached constant values.

5 0
3 years ago
A container with 3.0 moles of gas has a volume of 60.0L with a temperature at 400.K what is the pressure
iris [78.8K]

Answer: P= 1.64 atm

Explanation: solution attached.

Use Ideal gas law

PV= nRT

Derive for P

P= nRT/V R= 0.08205 L.atm/mol.K

Substitute the values.

3 0
3 years ago
How many grams of aluminum chloride are needed to react completely with 1.084g lithium sulfide?
Oksi-84 [34.3K]
Molar mass :

Li₂S = <span>45.947 g/mol

AlCl</span>₃ = <span>133.34 g/mol

</span><span>3 Li</span>₂<span>S + 2 AlCl</span>₃<span> = 6 LiCl + Al</span>₂S₃

3 * 45.947 g Li₂S ----------> 2 * <span>133.34 g AlCl</span>₃
1.084 g Li₂S ----------------> ?

Mass Li₂S = 1.084 * 2 * 133.34 / 3 * 45.947

Mass Li₂S = 289.08112 / 137.841

Mass Li₂S = 2.0972 g 

hope this helps!

5 0
3 years ago
2. Nitric oxide contains 46.66% nitrogen and 53.34% oxygen. Water contains 11.21% hydrogen and 88.79% oxygen. Ammonia contains 1
Mrrafil [7]

Answer:

The law of reciprocal proportions states that if two elements react individually with a given weight of a third element, the ratio of the masses with which they combine with the third element are either the same or a simple multiple of the ratio of the masses with which they combine with each other

The compounds formed includes;

1) Nitric oxide, NO

Nitrogen = 46.66% × 30.01 = 14

Oxygen = 53.34% × 30.01 = 16

2) Water, H₂O

Hydrogen = 11.21% × 18.01528 = 2

Oxygen = 88.79% × 18.01528 ≈ 16

3) Ammonia, NH₃

Hydrogen = 17.78% × 17.031 ≈ 3

Nitrogen = 82.22% × 17.031 ≈ 14

The ratio of nitrogen to oxygen in nitric oxide = 14:16 = 7:8

The ratio of nitrogen to hydrogen in ammonia = 14:3

The ratio in which hydrogen and oxygen combine with nitrogen = 3/16

The ratio of hydrogen and oxygen combine with each other in water = 2/16

Therefore, the ratio with which hydrogen and oxygen combine with nitrogen, is (2/3) times the ratio with which they combine with each other, which verifies the law of reciprocal proportions

Explanation:

4 0
3 years ago
Convert 1.39 x 10^24 atoms of carbon to moles of carbon
Nimfa-mama [501]
If 1mol ------- is ----------- 6,02×10²³
so x     ------- is ----------- 1,39×10²⁴

x=\frac{1,39*10^{24}*1mol}{6,02*10^{23}}\approx2,31mol
8 0
3 years ago
Read 2 more answers
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