All categories

2 years ago

(Dear brainly, you can't delete this question caue its about school work too)

Chemistry

2 answers:

NeTakaya2 years ago

5 0

Answer:

70% to 100% is the highest grade, a mark of Distinction. 60% to 69% earns a Merit. 50% to 59% is Pass.is what im guessing and if your grade is 90.5 and has lowerd or hasn't that is ok because it might lower to a c but i advise to work better and if it is just a 90.5 overall including the test score that is fine nbut you will pass is what im think

Explanation:

Try better next time :) hope i help so you pass im ptretty sure and if you dont just be a tryhard

STatiana [176]2 years ago

4 0

I don’t understand your question but It looks like the another person answered it already did

You might be interested in

Which of the following statements best describes the current atomic theory

Oksana_A [137]

You did not provide the statements but a possible answer might be that the current atomic theory is sound and that technology that could challenge it does not exist at this time. There is no way to change it because no research can be done about it.

8 0

3 years ago

The vapor pressure of diethyl ether (ether) is 463.57 mm Hg at 25 °C. A nonvolatile, nonelectrolyte that dissolves in diethyl et

Alexxx [7]

Answer: The vapor pressure of solution is 459.17 mmHg

Explanation:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ .....(1)

For testosterone:

Given mass of testosterone = 7.752 g

Molar mass of testosterone = 288.4 g/mol

Putting values in equation 1, we get:

$\text{Moles of testosterone}=\frac{7.752g}{288.4g/mol}=0.027mol$

For diethyl ether:

Given mass of diethyl ether = 208.0 g

Molar mass of diethyl ether = 74.12 g/mol

Putting values in equation 1, we get:

$\text{Moles of diethyl ether}=\frac{208.0g}{74.12g/mol}=2.81mol$

Mole fraction of a substance is calculated by using the equation:

$\chi_A=\frac{n_A}{n_A+n_B}$

$\chi_{\text{testosterone}}=\frac{n_{\text{testosterone}}}{n_{\text{testosterone}}+n_{\text{diethyl ether}}}$

$\chi_{\text{testosterone}}=\frac{0.027}{0.027+2.81}\\\\\chi_{\text{testosterone}}=0.0095$

The formula for relative lowering of vapor pressure will be:

$\frac{p^o-p_s}{p^o}=i\times \chi_{\text{solute}}$

where,

$p^o$ = vapor pressure of solvent (diethyl ether) = 463.57 mmHg

$p^s$ = vapor pressure of the solution = ?

i = Van't Hoff factor = 1 (for non electrolytes)

$\chi_{\text{solute}}$ = mole fraction of solute (testosterone) = 0.0095

Putting values in above equation, we get:

$\frac{463.57-p^s}{463.57}=1\times 0.0095\\\\p^s=459.17mmHg$

Hence, the vapor pressure of solution is 459.17 mmHg

7 0

3 years ago

What is the molality of a solution

vitfil [10]

Molarity (M) is the concentration of a solution expressed as the number of moles of solute per liter of solution: Molarity (M) = moles solute. liters solution.

5 0

2 years ago

Read 2 more answers

The pH of a solution is measured as 4.5. What is the hydrogen ion concentration of the solution?

Bond [772]

Answer:

[H⁺] = 3.16 × 10⁻⁵ mol/L

Explanation:

Given data:

pH of solution = 4.5

Hydrogen ion concentration = ?

Solution;

pH = -log [H⁺]

we will rearrange this formula:

[H⁺] = 10∧-pH

[H⁺] = 10⁻⁴°⁵

[H⁺] = 3.16 × 10⁻⁵ mol/L

4 0

2 years ago

A student uses 5g of carbon to extract copper metal from its ore:

Umnica [9.8K]

Answer:

drt4gxhknwo

Explanation:

4 0

2 years ago