Ask question

Ask question

All categories

Thepotemich [5.8K]

3 years ago

13

Which of these are true for a hypothesis? (You can pick more than one)

1 answer:

Naya [18.7K]3 years ago

6 0

Hypotheisis is just like an initial building block for a building. The true statements about hypothesis among the given are-

First guess- hypothesis is a proposed explanation for something which is observed. Thus the explanation is just a guess and not a proved one.
An initial idea which is assumed to be true - The whole experiment or research is based on an assumption which is supposed to be true and the scientist works to prove that true.

You might be interested in

Calculate the number of grams of sodium chloride in the solution. (Hint: Remember that sodium chloride is a strong electrolyte.)

creativ13 [48]

The question is incomplete, here is the complete question:

A solution contains 0.115 mol $H_2O$ and an unknown number of moles of sodium chloride. The vapor pressure of the solution at 30°C is 25.7 torr. The vapor pressure of pure water at this temperature is 31.8 torr. Calculate the number of grams of sodium chloride in the solution. (Hint: Remember that sodium chloride is a strong electrolyte.)

<u>Answer:</u> The mass of sodium chloride in the solution is 0.714 grams

<u>Explanation:</u>

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 (water) = 31.8 torr

$p^s$ = vapor pressure of the solution = 25.7 torr

i = Van't Hoff factor = 2

$\chi_{\text{solute}}$ = mole fraction of solute (sodium chloride) = ?

Putting values in above equation, we get:

$\frac{31.8-25.7}{31.8}=2\times \chi_{NaCl}\\\\\chi_{NaCl}=0.0959$

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

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

$\chi_{\text{NaCl}}=\frac{n_{\text{NaCl}}}{n_{\text{NaCl}}+n_{\text{water}}}$

We are given:

Moles of water = 0.115 moles

$0.0959=\frac{n_{\text{NaCl}}}{n_{\text{NaCl}}+0.115}\\\\n_{\text{NaCl}}=0.0122mol$

To calculate the mass for given number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Moles of NaCl = 0.0122 moles

Molar mass of NaCl = 58.5 g/mol

Putting values in above equation, we get:

$0.0122mol=\frac{\text{Mass of NaCl}}{58.5g/mol}\\\\\text{Mass of NaCl}(0.0122mol\times 58.5g/mol)=0.714g$

Hence, the mass of sodium chloride in the solution is 0.714 grams

5 0

3 years ago

Which statement correctly compares an atom of an alkali metal with an atom of the alkaline earth metal next to it on the periodi

Mumz [18]

<span>The alkali metal atom forms a +1 ion, while the alkaline earth metal atom forms a +2 ion. hope this helps</span>

6 0

3 years ago

Is Carbon combustible? Why or why not?

valkas [14]

Carbon is not combustible because when it combines with oxygen its energy increases thus it doesnt combust.

3 0

3 years ago

A chef fills a 50ml container with 43.5g of cooking oil. whats the density of the oil

jasenka [17]

I believe the answer is .87g/mL. But I'm not sure so whatevs

4 0

3 years ago

Help!!!!?????????? plssssssss

DIA [1.3K]

Answer: it’s b)

Explanation: that’s the only difference that is listed

4 0

3 years ago

Read 2 more answers