All categories

2 years ago

How many moles of sodium carbonate are contained by 57.3g of sodium carbonate

Chemistry

1 answer:

Lady_Fox [76]2 years ago

6 0

Answer:

$\boxed {\boxed {\sf 0.541 \ mol \ Na_2CO_3}}$

Explanation:

We are asked to find how many moles of sodium carbonate are in 57.3 grams of the substance.

Carbonate is CO₃ and has an oxidation number of -2. Sodium is Na and has an oxidation number of +1. There must be 2 moles of sodium so the charge of the sodium balances the charge of the carbonate. The formula is Na₂CO₃.

We will convert grams to moles using the molar mass or the mass of 1 mole of a substance. They are found on the Periodic Table as the atomic masses, but the units are grams per mole instead of atomic mass units. Look up the molar masses of the individual elements.

Na: 22.9897693 g/mol
C: 12.011 g/mol
O: 15.999 g/mol

Remember the formula contains subscripts. There are multiple moles of some elements in 1 mole of the compound. We multiply the element's molar mass by the subscript after it, then add everything together.

Na₂ = 22.9897693 * 2= 45.9795386 g/mol
O₃ = 15.999 * 3= 47.997 g/mol
Na₂CO₃= 45.9795386 + 12.011 + 47.997 =105.9875386 g/mol

We will convert using dimensional analysis. Set up a ratio using the molar mass.

$\frac {105.9875386 \ g \ Na_2CO_3}{1 \ mol \ Na_2CO_3}$

We are converting 57.3 grams to moles, so we multiply by this value.

$57.3 \ g \ Na_2CO_3} *\frac {105.9875386 \ g \ Na_2CO_3}{1 \ mol \ Na_2CO_3}$

Flip the ratio so the units of grams of sodium carbonate cancel.

$57.3 \ g \ Na_2CO_3} *\frac {1 \ mol \ Na_2CO_3}{105.9875386 \ g \ Na_2CO_3}$

$57.3 } *\frac {1 \ mol \ Na_2CO_3}{105.9875386 }$

$\frac {57.3 }{105.9875386 } \ mol \ Na_2CO_3$

$0.5406295944 \ mol \ Na_2CO_3$

The original measurement of moles has 3 significant figures, so our answer must have the same. For the number we found that is the thousandth place. The 6 in the ten-thousandth place to the right tells us to round the 0 up to a 1.

$0.541 \ mol \ Na_2CO_3$

There are approximately 0.541 moles of sodium carbonate in 57.3 grams.

You might be interested in

Explain how index minerals allow a scientist to understand the history of a metamorphic rock?

Masteriza [31]

It allows a scientist to understand the history of metamorphic rock by estimating the temperature, depth, and pressure at which a rock undergoes metamorphism. Hope that helped!

5 0

2 years ago

Read 2 more answers

What does pressure measure

omeli [17]

Answer:

Explanation:

Pressure it says it in the name its the force of colliding particles

6 0

3 years ago

A specific brand of gourmet chocolate candy contains 7.00 g of dietary fat in each 22.7-gpiece. How many kilograms of dietary fa

Genrish500 [490]

Answer: 0.14 kg

Explanation:

Gourmet chocolate candy contains 7.00 g of dietary fat in each 22.7-g piece

That is 1 piece of candy weighs 22.7 g and contains 7.00 g of dietary fat

Converting the mass in pounds to kg

1 lb = 0.45 kg = 450 grams (1kg=1000g)

Number of pieces = $\frac{450}{22.7g}=20pieces$

1 piece contains = 7 g of dietary fat

Thus 30 pieces would contain = $\frac{7}{1}\times 20=140g$ of dietary fat

1 g = 0.001 kg

Thus 140 grams = $\frac{0.001}{1}\times 140=0.14kg$

Thus 0.14 kg of dietary fat are in a box containing 1.00 lb of candy.

5 0

3 years ago

If 25 mL of a HCl solution of unknown concentration was neutralized with 10 mL of a 0.30 M NaOH solution, what was the original

QveST [7]

Answer:

0.12 M

Explanation:

Step 1: Write the balanced equation

NaOH + HCl ⇒ NaCl + H₂O

Step 2: Calculate the reacting moles of NaOH

10 mL of a 0.30 M NaOH solution react.

$0.010L \times \frac{0.30mol}{L} = 3.0 \times 10^{-3} mol$

Step 3: Calculate the reacting moles of HCl

The molar ratio of NaOH to HCl is 1:1. The reacting moles of HCl are 1/1 × 3.0 × 10⁻³ mol = 3.0 × 10⁻³ mol.

Step 4: Calculate the concentration of HCl

3.0 × 10⁻³ mol of HCl are in 25 mL of solution.

$M = \frac{3.0 \times 10^{-3} mol}{0.025L} = 0.12 M$

5 0

3 years ago

In the early twentieth century, what was Alexander Fleming’s hypothesis concerning the relationship between a yellow-green mold

SpyIntel [72]

Answer:

The correct answer is the option c)He thought the mold had released a chemical that prevented the bacteria’s growth.

Explanation:

In the 1920s, Alexander Fleming was working in his laboratory at St. Mary's Hospital in London when, almost by accident, he discovered a naturally growing substance that could attack certain bacteria. In one of his experiments, Fleming observed that colonies of a bacterium had been depleted or removed by a mold that grew on the same Petri dish. He observed that the bacteria furthest from the fungus had grown to produce large-sized colonies, while the colonies closest to the fungus were tiny. He determined that mold made a substance that could dissolve bacteria. The fungus was penicilium chrysogenum and thus Fleming called this substance penicillin, by the name of the mold that produces it. Thus, after several years of experiments in 1930, Howard Florey and Ernest Chain developed at Oxford University the procedures to produce pure penicillin from the fungus that Fleming isolated. Thus penicillin could be concentrated by Florey and Chain, and in 1945 they shared with Fleming the Nobel Prize in Medicine.

Then, the correct answer is the option c)He thought the mold had released a chemical that prevented the bacteria’s growth.

4 0

2 years ago