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2 years ago

PLEASE

Chemistry

1 answer:

sesenic [268]2 years ago

7 0

Answer:

How many grams of H2 can be produced from the reaction of 11.5 grams of sodium with an excess of water? Hint: 2Na + 2H2O ---> 2NaOH + H2. Ans: 0.505g .

Explanation:

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How is separating a compound more complicate that separating parts of a mixture

sineoko [7]

You can use physical methods to separate a mixture and also some chemical methods too.
Mixture is just a physical combine.
However a compound is a chemical combine so you must use special methods to separate it

8 0

3 years ago

How many grams of nacl are required to make 500.0 ml of a 1.500 m solution?

mestny [16]

<span>43.83g of nacl are required to </span><span>make 500.0 ml of a 1.500 m solution.</span>

4 0

3 years ago

Read 2 more answers

Can somebody help me with this also plz

just olya [345]

ANSWER:

4 a) Specific elements have more than one oxidation state, demonstrating variable valency.

For example, the following transition metals demonstrate varied valence states: $Fe^{2+}$ , $Fe^{3+}$ , $Cr^{2+}, Cr^{3+}$ , etc.

Normal metals such as $Pb^{2+} and Pb^{4+}$ also show variable valencies. Certain non-metals are also found to show more than one valence state $Pb^{3+} and Pb^{5+}.$

4 b) Isotopes are members of a family of an element that all have the same number of protons but different numbers of neutrons.

For example, Carbon-14 is a naturally occurring radioactive isotope of carbon, having six protons and eight neutrons in the nucleus. However, C-14 does not last forever and there will come a time when it loses its extra neutrons and becomes Carbon-12.

5 a) $2Fe + 3Cl_2$ → $2FeCl_3$

5 b) $3Pb + 8HNO_3$ → $3Pb (NO_3)_2 + 4H_2O + 2NO_2$

5 c) $Zn + H_2SO_4$ → $ZnSO_4 + H_2$ (already balanced so don't need to change)

5 d) $2H_2 + O_2$ → $2H_2O$

5 e) $2Mg + 2HCl$ → $2MgCl + H_2$

EXPLANATION (IF NEEDED):

1. Write out how many atoms of each element is on the left (reactant side) and right (product side) of the arrow.

2. Start multiplying each side accordingly to try to get atoms of the elements on both sides equal.

EXAMPLE OF BALANCING:

8 0

3 years ago

What point A on the phase diagram called?

Mariana [72]

Answer:

D) the critical point

Explanation:

Point A is the critical point in phase diagram. This is the highest temperature and pressure at which a pure material can exist in vapor/liquid equilibrium. Pretty cool!

6 0

3 years ago

When hydrogen gas reacts with oxygen gas under certain conditions to produce liquid water, 572.0 kJ of heat energy is released.

frozen [14]

Answer : This reaction is an exothermic reaction.

Explanation :

Endothermic reaction : It is defined as the chemical reaction in which the energy is absorbed from the surrounding.

In the endothermic reaction, the energy of reactant are less than the energy of product.

Exothermic reaction : It is defined as the chemical reaction in which the energy is released into the surrounding.

In the exothermic reaction, the energy of reactant are more than the energy of product.

Enthalpy of reaction : It is the difference between the energy of product and the reactant. It is represented as $\Delta H$ .

The balanced chemical reaction will be:

$H_2(g)+O_2(g)\rightarrow H_2O(l)+572.0kJ$

From the reaction we conclude that the heat energy is released during the reaction that means this reaction is an exothermic reaction.

Hence, the reaction is an exothermic reaction.

7 0

4 years ago