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3 years ago

Calculate the mass percent (m/m) of a solution prepared by dissolving 55.84 g of nacl in 152.7 g of h2o.

1 answer:

7 0

M(NaCl)=55.84 g
m(H₂O)=157.2 g

m(solution)=m(NaCl)+m(H₂O)

w(NaCl)=100m(NaCl)/m(solution)=100m(NaCl)/(m(NaCl)+m(H₂O))

w(NaCl)=100*55.84/(55.84+152.7)=26.78%

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12.00 moles of naclo3 will produce how many grams of O2? (Moles to Grams)

Sergeu [11.5K]

2NaClO₃ → 2NaCl + 3O₂

mole ratio of NaClO₃ to O₂ is 2 : 3

∴ if moles of NaClO₃ = 12 mol

then moles of O₂ = $\frac{12 mol * 3}{2}$

= 18 mol

Mass of O₂ = mol of O₂ × molar mass of O₂

= 18 mol × 16 g/mol

= 288 g

So I wasn't sure which equation to use since you did not specify so I just used the decomposition reaction. If you should have used another reaction then just follow the same steps and you'll get your answer.

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3 years ago

student mixes vinegar and baking soda inside a sealed plastic bag would the reaction be the same if baking soda and vinegar were

pychu [463]

Yes, because nothing has changed. The same ingredients are used and if one reaction happened in a a bag then why wouldn’t it happen in a container?

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3 years ago

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Svet_ta [14]

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7 0

3 years ago

Suppose that you add 28.8 g of an unknown molecular compound to 0.250 kg of benzene, which has a K f Kf of 5.12 oC/m. With the a

Brrunno [24]

Answer:

THE MOLAR MASS OF THE UNKNOWN COMPOUND IS 242.02 g/mol.

Explanation:

First:

Calculate the change in freezing point:

Freezing point of pure benzene = 5.5°C

Change in temperature = 5.5 - 3.06 = 2.44 °C

Second:

Using the formula:

Δt = i Kf m

Let's assume i = 1

Kf = 5.12 °C/m

M = x / 0.250 kg of benzene

Then we can calculate x which is the molarity

Re-arranging the formula, we have:

m = Δt / i Kf

x / 0.250 = 2.44 / 1 * 5.12

x = 2.44 * 0.250 / 5.12

x = 0.61 / 5.12

x = 0.119 M

Since it is well known that molarity is the mass of a substance divided by its molar mass. We can then calculate the molar mass.

Molar mass = Mass / molarity

Molar mass = 28.8 g / 0.119 M

Molar mass =242.02 g/mol

Hence, the molar mass of the unknown molecular compound is 242.02 g/mol.

4 0

3 years ago

You are unsure of the volume of a substance, but you know that it has a density of 4 g/ml and a mass of 16 grams. What is its vo

avanturin [10]

Answer:

4 mL

Explanation:

Use the density formula, d = m/v

Plug in the density and mass to solve for v:

4 = 16/v

4v = 16

v = 4

So, the volume is 4 mL

3 0

3 years ago