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4 years ago

This is the chemical formula for talc Mg3(Si2O5)2(OH)2(the main ingredient in talcum powder):

Chemistry

1 answer:

Elena-2011 [213]4 years ago

8 0

Answer:

0.022 mol O

Explanation:

Mg3(Si2O5)2(OH)2

We can see that 1 mol of this substance has 3 mol of Mg.

Oxygen altogether is 5*2 (from (Si2O5)2) + 2(from(OH)2) = 10 +2 = 12

So, 1 mol of this substance has 12 mol oxygen.

So, 1 mol of this substance contains 3 mol Mg and 12 mol O, or

ratio Mg : O = 3 : 12 = 1 : 4

1 mol Mg ----- 4 mol O

0.055 mol Mg ---x mol O

x = 0.055*4/1 = 0.220 mol O

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Which of the following statements would be the hypothesis most easily tested? a) Oak trees grow tallest between temperatures of

shepuryov [24]

Answer: a) Oak trees grow tallest between temperatures of 10 and 40 degrees

Explanation:

This hypothesis is specific, can be tested (though perhaps not easily), and is well set up.

Hope this helps! :)

7 0

4 years ago

2.25 g/ml at 700mmHg, 200 C. Find molar mass of gas.

Harrizon [31]

Answer:

Molar mass = 94972.745 g/mol

Explanation:

Given data:

Density = 2.25 g/ml

Pressure = 700 mmHg

Temperature = 200°C

Molar mass = ?

Solution:

Density = 2.25 g/ml (2.25×1000 = 2250 g/L)

Pressure = 700 mmHg (700/760 = 0.92 atm)

Temperature = 200°C (200+273 = 473K)

Formula:

d = PM/RT

M = dRT/P

M = 2250 g/L × 0.0821 atm.L /mol.K × 473K / 0.92 atm

M = 87374.93 g/mol / 0.92

M = 94972.745 g/mol

6 0

4 years ago

You want to determine the protein content in milk with the Kjeldahl method. You take 100 g whole milk and use 100 mL of 0.5 M hy

stepladder [879]

Answer:

3.38%

Explanation:

Given that;

the mass of the whole milk sample = 100 g

volume of HCl = 100 mL = 0.1 L

molarity of HCl = 0.5 M

volume of NaOH = 34.50 mL = 0.0345 L

molarity of NaOH = 0.3512 M

Since we knew the molarity and volume of both HCl and NaOH; we can calculate their corresponding number of moles present.

So, number of moles of HCl = molarity of HCl × volume of HCl

number of moles of HCl = 0.5 M × 0.100 mL

= 0.05 mole

number of moles of NaOH = Molarity of NaOH × Volume of NaOH

number of moles of NaOH = 0.3512 M × 0.0345 L

= 0.012 mole

From the question, we can deduce that the number of HCl that is consumed by NH₃ is equal to the number of moles of HCl that is consumed by NaOH.

SO, number of moles of HCl consumed by NH₃ = Total moles of HCl - moles of HCl consumed by NaOH

= 0.05 mole - 0.012 mole

= 0.038 mole

However, to determine the mole of NH₃ present , we have:

number of moles of NH₃ present = number of moles of HCl consumed by NH₃ = 0.038

∴ the mass of Nitrogen with the molecular weight (14.0 g/mol) = 0.038 moles × 14.0 g/mol

= 0.530 g

Now, the percentage of Nitrogen can be calculated as;

$percentage of nitrogen =\frac{mass of nitrogen}{mass of the whole milk sample} *100$

$percentage of nitrogen =\frac{0.530g}{100g} *100$

$percentage of nitrogen =0.530%$ %

the percentage of protein in the sample = CP × %age of N

where CP is given as 6.38

∴ the percentage of protein in the sample = 6.38 × 0.530%

the percentage of protein in the sample = 3.3814%

the percentage of protein in the sample = 3.38%

6 0

4 years ago

quester [9]

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7 0

3 years ago

HELP ASAS 15 POINTS

kramer

Answer:

liquid will be evaporated while solid remains

3 0

3 years ago