Which is the correct answer?

Compared to other minerals, a mineral that is ranked higher on the mohs scale will be

Step2247 [10]

A mineral ranked higher in the mohs scale is relatively harder than other minerals. Mohs scale lists 10 minerals from the softest to hardest. The hardest mineral is diamon while the softest one is talc. The two minerals compared are scratched with each other. The scratched one is the softer mineral.

6 0

3 years ago

10.0 grams of water are heated during the preparation of a cup of coffee 1.0x 103 j of the heat are added to the water. which is

nirvana33 [79]

Answer: The final temperature of the coffee is 43.9°C

Explanation:

To calculate the final temperature, we use the equation:

$q=mC(T_2-T_1)$

where,

q = heat released = $1.0\times 10^3J=1000J$

m = mass of water = 10.0 grams

C = specific heat capacity of water = 4.184 J/g°C

$T_2$ = final temperature = ?

$T_1$ = initial temperature = 20°C

Putting values in above equation, we get:

$1000J=10.0g\times 4.184J/g^oC\times (T_2-20)\\\\T_2=43.9^oC$

Hence, the final temperature of the coffee is 43.9°C

8 0

3 years ago

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.)

Answer: The mass of sodium chloride in the solution is 0.714 grams

Explanation:

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

Briefly compare and contrast the relative resistance to ph change of the seven solutions

JulsSmile [24]

PH stands for "Potential Hydrogen" and the PH scale ranges from 0-14. PH refers to the ability to attract hydrogen ions.

The PH of a solution either indicates acidity of the solution or alkalinity of the solution. A solution which has PH 7 above is a base solution where a solution with PH less than 7 is an acidic solution.

6 0

3 years ago

The use of crucible

Norma-Jean [14]

a ceramic or metal container in which metals or other substances may be melted or subjected to very high temperatures.

"the crucible tipped and the mold filled with liquid metal"

a situation of severe trial, or in which different elements interact, leading to the creation of something new.

"their relationship was forged in the crucible of war"

3 0

3 years ago