All categories

4 years ago

How many molecules are there in 840 grams of na2SO4

Chemistry

1 answer:

beks73 [17]4 years ago

4 0

Answer:

3.56x10^24 molecules

Explanation:

The following data were obtained from the question:

Mass of Na2SO4 = 840g

Molar Mass of Na2SO4 = (23 x2) + 32 + (16x4) =46 + 12 + 64 = 142g/mol

From Avogadro's hypothesis, 1mole of any substance contains 6.02x10^23 molecules. This also gives that 1mole of Na2SO4 contains 6.02x10^23 molecules.

If 1 mole (i.e 142g) contains 6.02x10^23 molecules,

Therefore, 840g of Na2SO4 will contain = (840 x 6.02x10^23)/142 = 3.56x10^24 molecules

You might be interested in

Which example best describes a reflex action?

Pepsi [2]

I think the answer would be b because your throat is reacting to the cough?

6 0

3 years ago

What enzymes Break it down sugar ???

tatyana61 [14]

Amylase has the process in which it breaks down of sugars when you’re having carbohydrates

6 0

3 years ago

To measure the volume of the blood system of an animal, the following experiment was done. A 1.0-mL sample of an aqueous solutio

Artyom0805 [142]

Answer:199mL

Explanation:

Let V ml be the volume of blood in animal.

When 1.0 ml sample is added, total volume becomes V+1.0ml. Its activity is 1000 dpm.

After equilibrium, 2.0 ml of the sample had activity of 10 dpm.

Hence, after equilibrium, the activity of V+1.0 ml of blood sample will be 10/2 (V+1.0ml)=1000dpm

Hence, V=199ml.

4 0

3 years ago

Which of the following increases as the concentration of a colored solution increases? wavelenght transmittance absorbance b) A

iris [78.8K]

Answer:

a) Absorbance

b) The absorb light most strongly in 580nm

Explanation:

Beer-Lambert law relates concentration with light absorbance. The more concentrated solution are the more molecules and the most absorbance.

Wavelenght depends of composition of solution and doesn't change with different concentrations of the same solution.

Transmittance is inversely proportional to absorbance. Thus, the more concentrated solution the less transmittance.

Colored compounds are absorb energy of visible radiation. The colour that we see is a result of the absortion of complimentary colour (Colour wheel). Thus, a blue-green solution absorb energy of ≈600 nm. Thus, the absorb light most strongly in 580nm.

I hope it helps!

6 0

4 years ago

How many moles of NaF are produced in the resction between sodium bromide and calcium fluoride when 550 grams of sodium bromide

bija089 [108]

Answer: 5 moles of NaF would be produced when 550 grams of Sodium bromide are used.

Explanation:

From the question, the balanced chemical formula is illustrated below:

2NaBr + CaF2 → 2NaF + CaBr2

From the equation above;

Molecular mass of NaBr = 23 + 80 = 103g/ mol

Molecular mass of CaF2= 40+ (19×2)= 78g/ mol

Molecular mass of NaF = 23+19 = 42g/ mol

From the balanced chemical equation;

2 moles of NaBr reacted with 1mole of CaF to give 2 moles of NaF.

That is, 2 moles of NaBr= 2× 103 = 206g

2moles of NaF = 2×42= 84g

If 206g of NaBr yielded 84g of NaF

Therefore 550g of NaBr will yield Xg of NaF

X= 550×84/206

X= 224.27g of NaF

But 42g = 1 mole of NaF

Therefore 224.27g = X mole of NaF

X= 224.27 ×1/42

X is approximately 5moles.

6 0

3 years ago