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3 years ago

Please Help 8-9!!!!!!!

Chemistry

1 answer:

seropon [69]3 years ago

3 0

The labeled diagram is given in the image attached.

As it can be seen from the image that freezing is when energy is removed from the system at 0 ⁰ while melting is when energy is added at 0⁰.

Also when energy is added at 100⁰C, it causes boiling while when it is removed at 100⁰C, it causes condensation.

Melting point of water is 0⁰C while boiling point is 100⁰C

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Sam prepares a solution of sodium chloride with a concentration of 8 g/dm³. If he only used 2g of sodium chloride, what volume o

adoni [48]

The volume of water he dissolved the solute is 250 cubic centimeter.

Explanation:

Concentration = mass of solute in g / volume in dm^3

The concentration of a solution is defined as the ratio of mass of solute in grams to the volume of water in dm^3.

If concentration of a solution = 8 g/dm^3.

mass of solute =2 g.

Volume of a water = 2 / 8 = 0.25 dm^3. (or) 250 cubic centimeter.

4 0

3 years ago

The number of ions produced when a substance dissolves is always equal to the number of Adams in a chemical formula. What is inc

german

One thing incorrect is that when dealing with a compound, such as H2SO4, that has 7 atoms in the chemical formula, the polyatomic ion SO4 doesn’t dissociate into one Sulfur and four Oxygens. SO4 stays and a PAI.

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3 years ago

Describe the activities to prove that Liquid exerts pressure equally and perpendicularly in all direction

Vlad1618 [11]

Step by step explanation
1.First take a bottle and fill it with water
2.mark points on the bottle in any level four directions perpendicularly
3.make a hole in the points you have marked
Observation
The liquid exerts pressure equally and perpendicularly in all directions

Hope this answer helps

7 0

3 years ago

What was John Dobereiner’s contribution to the development of the periodic table

erastova [34]

John Dobereiner proposed the idea of similarity in the properties of elements which can be placed together.

He proposed the idea of classification so that we can study the properties of a group of elements together

According to him, three elements can be grouped based on their similarities in properties. This group of three elements was termed as "Triads"

For example :

Li, Na, K

Now the significance of the triad was that the atomic weight of middle element is average of atomic weights of the side atoms

So atomic weight of Na = 23 is average of atomic weights of Lithium and Potassium

7 + 39/2 = 46/2= 23

The other triads were

Ca Sr Ba

Cl Br I

S Se Te

5 0

4 years ago

Select the reagent that will separate the pairs of ions listed.

daser333 [38]

1 - a, 2-b, 3-d, 4 - e

Explanation:

$A g^{+} \text {and } A l^{3+}$ - Separated by 6M HCl

Silver and aluminum ions can be separated using the acid, 6M HCl.

$C u^{2+} \text { and } C a^{2+}$ - Separated by H₂S

Copper and Calcium ions can be separated by the reagent hydrogen sulfide, H₂S.

$M g^{2+} \text { and } K^{+}$ - Separated by (NH₄)₂HPO₄ in NH₃

Magnesium and Potassium ions can be separated by the reagent Ammonium hydrogen phosphate in ammonia.

$N i^{2+} \text { and } C o^{2+}$ - cannot be separated

Nickel and Cobalt ion cannot be separated by the reagents given at all.

8 0

3 years ago