Which contains 3 significant figures.

Three mixtures were prepared from three very narrow molar mass distribution polystyrene samples with molar masses of 10,000, 30,

8_murik_8 [283]

Answer:

(a). 46,666.7 g/mol; 78,571.4 g/mol

(b). 86950g/mol; 46,666.7 g/mol.

(c). 86950g/mol; 43,333.33 g/mol

Explanation:

So, we are given the molar masses for the three samples as: 10,000, 30,000 and 100,000 g mol−1.

Thus, the equal number of molecule in each sample = ( 10,000 + 30,000 + 100,000 ) / 3 = 46,666.7 g/mol.

The average molar mass = [ ( 10,000)^2 + (30,000)^2 + 100,000)^2] ÷ 10,000 + 30,000 + 100,000 = 78,571. 4 g/mol.

(b). The equal masses of each sample = 3/[ ( 1/ 10,000) + (1/30,000 ) + (1/100,000) ] = 20930.23 g/mol.

Average molar mass = ( 10,000 + 30,000 + 100,000 ) / 3 = 46,666.7 g/mol.

(c). Equal masses of the two samples = (0.145 × 10,000) + (0.855 × 100,000)/ 0.145 + 0.855 = 86950g/mol.

The weight average molar mass = 1.7 + 10,000 + 100,000/ 1.7 + 1 = 43,333.33 g/mol.

6 0

2 years ago

Separates substances on the basis of the boiling points of the substances

kiruha [24]

B. Distillation
Distilling is when you boil a substance and collect the vapors.

3 0

2 years ago

Clearly distinguish between science and technology

tia_tia [17]

Answer:

The words science and technology can and often are used interchangeably. But the goal of science is the pursuit of knowledge for its own sake while the goal of technology is to create products that solve problems and improve human life. Simply put, technology is the practical application of science.

Explanation:

Check the following images

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3 0

3 years ago

Identify limiting and excess reagents when 25g of nitrogen reacts with 25g of hydrogen. How many grams of ammonia gas are formed

Makovka662 [10]

Answer:

Nitrogen is limiting reactant while hydrogen is in excess.

Explanation:

Given data:

Mass of N₂ = 25 g

Mass of H₂ = 25 g

Mass of ammonia formed = ?

Solution:

Chemical equation:

N₂ + 3H₂ → 2NH₃

Number of moles of Nitrogen:

Number of moles = mass/ molar mass

Number of moles = 25 g/ 28 g/mol

Number of moles = 0.89 mol

Number of moles of hydrogen:

Number of moles = mass/ molar mass

Number of moles = 25 g/ 2 g/mol

Number of moles = 12.5 mol

Now we will compare the moles of both reactant with ammonia.

H₂ ; NH₃

3 : 2

12.5 : 2/3×12.5 = 8.3

N₂ ; NH₃

1 : 2

0.89 : 2×0.89 = 1.78

The number of moles of ammonia produced by nitrogen are less thus nitrogen is limiting reactant while hydrogen is in excess.

7 0

3 years ago

Is butanol a liquid or a solid at -40*C? Explain how you determined this. <br> MAJOR HELP NEEDED!!!

ASHA 777 [7]

Answer:

solid

Explanation:

3 0

2 years ago