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3 years ago

Which statement about atoms and molecules is

Chemistry

2 answers:

Pavel [41]3 years ago

8 0

Elements always exist as pair of atoms called molecules .

Explanation:-

The material which has only one types of similar atoms called element .
Ex:-Sodium,Carbon etc

zhuklara [117]3 years ago

3 0

Answer:

Elements always exists as pairs of atoms called molecules

Explanation:

Elements are simply substances in its pure form.
The atom of an element is simply referring to a single element. eg we have sodium atom as Na, it appears singly and in its pure form
A molecule then refers to when an atom of the same element is paired up. i.e not in a single state. eg, we have one atom of hydrogen molecule as H2, Oxygen molecule as O2.
Note. the molecular elements appear in pairs while the atomic elements appear singly.

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Please somebody give me the answers

RSB [31]

Answer:

1. 9.4 grams of methane produce 25.85 grams of CO2

2.Grams of water produced = 11.81 grams

3.Mass of Methane produced by 10.1 gram of O2 = 2.52 grams

4.Amount of methane consumed = 46.9 grams

5. Grams of Co2 produced = 8.32 grams

Explanation:

Molar masses :

Methane = CH4 = mass of C + 4x (mass of H)

CH4 = 12 +4(1) = 16 grams

1 mole of CH4 = 16 gram

Oxygen O2 = 2 x (mass of O) = 2x(16) = 32 gram (1 mole of O2 =32 gram)

Carbon Dioxide =CO2 = mass of C + 2(mass of O)

= 12 + 2(16)

= 44 grams (1 mole of CO2 = 44 gram )

Water = H2O = 18 grams ( 1 mole of H2O = 18 gram)

1 mole of each molecule is equal to their molar masses

The balanced equation is :

$1CH_{4}(g)+2O_{2}\rightarrow 1CO_{2}+2H_{2}O(l)$

According to Stoichiometry :

1 mole of CH4 = 2 Mole of O2 = 1 mole of CO2 = 2 mole of H2O

1. From the equation ,

1 mole of methane produce =1 mole of CO2

16 gram of methane = 44 gram of CO2

1 gram of methane =

$\frac{44}{16}$ gram of CO2

9.4 gram of CH4 =

$\frac{44}{16}\times 9.4$ gram of CO2

= 25 .85 gram of CO2

2 mole of O2 produces = 2 mole of H2O(water)

1 mole of O2 produces = 1 mole of H2O

32 gram of O2 = 18 gram of water

1 gram of O2 =

$\frac{18}{32}$

21 gram of O2 =

$\frac{18}{32}\times 21$

11.81 gram of water

3. 1 mole of CH4 = 2 mole of O2

16 gram of CH4 = 2(32) = 64 grams of O2

64 gram of O2 needs = 16 grams of CH4

1 gram of O2 needs =

$\frac{16}{64}$

10.1 gram of O =

$\frac{16}{64}\times 10.1$ of CH4

= 2.52 gram

1 mole of CO2 is produced from = 1 mole of CH4

44 gram of CO2 is produced from 16 gram of CH4

1 gram CO2 =

$\frac{16}{44}$ gram of CH4

129 gram of CO2 =

$\frac{16}{44}\times 129$ gram of CH4

= 46.90 grams

2 mole of O2 produce = 1 mole of CO2

2x 32 gram of O2 = 44 gram of CO2

1 gram of O2 =

$\frac{44}{64}$ of CO2

12.1 gram of O2 produce=

$\frac{44}{64}\times 12.1$ of CO2

= 8.318 gram

Note : Write the quantity give on left side of "="

write the substance asked on right side of "="

8 0

3 years ago

9. Sodium reacts with water to produce sodium hydroxide and hydrogen gas, as shown below.

saveliy_v [14]

Answer:

Explanation:

2Na + 2H2O2==NaOh + H2

184/23=x/18

x=(184×18)/23

x=144g

4 0

3 years ago

The concentration of dye in Solution A is 26.609 M. You have 13 mL of water at your disposal to make the dilutions. The solution

exis [7]

Answer:

6,613 M

Explanation:

Dilution is the process of reducing the concentration of a solute in solution, mixing initial solution with more solvent.

The concentration of Solution B is:

23,881 M × = 9,552 M

Because the initial eight parts are diluted to 12+8 parts.

Thus, concentration of solution C is:

9,552 M × = 6,613 M

I hope it helps!

8 0

3 years ago

Which comppund contains both ionic and covalent bonds

Anna11 [10]

Answer:

potassium contains both Ionic and covalent bonds

3 0

1 year ago

What information would you find on a WHIMIS label?

Nady [450]

Answer/explanation:

Product identifier – the brand name, chemical name, common name, generic name or trade name of the hazardous product.
Initial supplier identifier – the name, address and telephone number of either the Canadian manufacturer or the Canadian importer.

8 0

2 years ago