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Alja [10]
3 years ago
6

3- There are 8 basic elements of life. True or false?

Chemistry
1 answer:
PolarNik [594]3 years ago
7 0

Answer: No that is false.

Explanation: There are 6 basic elements of life here they are. Have cells, have chemicals, respond to stimuli, reproduce, grow and develop, and use energy.

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In the Haber Process, hydrogen (H2) and nitrogen (N2) react to produce
lesya692 [45]

Answer:

Mass stays the same because no matter is created or destroyed.

Explanation:

Regardless of what chemical reaction we have, in each case the law of mass conservation applies. The law of mass conservation states that the total mass of a reaction mixture is kept constant, as mass cannot be created or destroyed.

In this specific reaction, the total mass of the reactants should be equal to the total mass of the products when the reaction is complete.

In other words, if we add the mass of hydrogen to the mass of nitrogen, when the reaction is compete, assuming no reagent in excess, this should be equal to the mass of ammonia formed.

7 0
3 years ago
Sodium peroxide (Na2O2) is often used in self-contained breathing devices, such as those used in fire emergencies, because it re
Anastaziya [24]

Answer:

725.15 L

Explanation:

The balanced chemical equation for the reaction between Na₂O₂ and CO₂ is the following:

Na₂O₂ + CO₂ → Na₂CO₃ + 1/2 O₂

From the stoichiometry of the reaction, 1 mol of Na₂O₂ reacts with 1 mol CO₂. So, the stoichiometric ratio is 1 mol Na₂O₂/1 CO₂.

Now, we convert the mass of reactants to moles by using the molecular weight (Mw) of each compound:

Mw (Na₂O₂) = (23 g/mol x 2) + (16 g/mol x 2) = 78 g/mol

moles Na₂O₂ = 96.7 g/(78 g/mol) = 1.24 mol Na₂O₂

Mw (CO₂) = 12 g/mol + (16 g/mol x 2) = 44 g/mol

moles CO₂ = 0.0755 g/(44 g/mol) = 1.71 x 10⁻³ mol CO₂

Now, we calculate the number of moles of CO₂ we need to completely react with the mass of Na₂O₂ we have:

1.24 mol Na₂O₂ x 1 mol CO₂/1 mol Na₂O₂ = 1.24 mol CO₂

In 1 L of respired air we have 1.71 x 10⁻³ mol CO₂ (0.0755 g), so we need the following number of liters to have 1.24 mol of CO₂:

1.24 mol CO₂ x 1 L/1.71 x 10⁻³ mol CO₂ = 725.15 L

4 0
3 years ago
Shay constructed a scientific model of the carbon cycle. She included plants, animals, industry, fossil fuels, and the atmospher
LenKa [72]

Answer:

no one can answer your question because you have shown no arrows.

3 0
2 years ago
Anything in red is the question
laila [671]

Answer:

  • Question 19: the three are molecular compounds.
  • Question 20: CuSO₄.5H₂O

Explanation:

<em>Question 19.</em>

  • C₂H₄
  • HF
  • H₂O₂

All of them are the combination of two kinds of different atoms in fixed proportions.

  • C₂H₄: two carbon atoms per four hydrogen atoms
  • HF: one hydrogen atom per one fluorine atom
  • H₂O₂: two hydrogen atoms per two oxygent atoms

Thus, they all meet the definition of compund: a pure substance formed by  two or more different elements with a definite composition.

Molecular compounds are formed by covalent bonds and ionic compounds are formed by ionic bonds.

Two non-metal elements, like H-F, C - C, C - H, H-O, H - H, and O - O will share electrons forming covalent bonds to complete their valence shell. Thus, the three compounds are molecular and not ionic.

<em>Question 20. </em>Formula of copper(II) sulfate hydrate with 36.0% water.

Copper(II) sulfate is CuSO₄. Its molar mass is 159.609g/mol

Water is H₂O. Its molar mass is 18.015g/mol

Calling x the number of water molecules in the hydrate, the percentage of water is:

       \dfrac{18.015x}{18.015x+159.609}=36\%\\ \\ \\ \dfrac{18.015x}{18.015x+159.609}=0.36

From which we can solve for x:

      18.015x=6.4854x+57.45924\\ \\ 11.5296x=57.45924\\ \\ x\approx4.98\approx5

Thus, there are 5 molecules of water per each unit of CuSO₄, and the formula is:

  • CuSO₄.5H₂O
4 0
3 years ago
Which statement best describes the effects chemicals may have on the
frutty [35]
The answer is B. So yeah
7 0
2 years ago
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