An mL is also equivalent to cm³, signifying that 140 mL is equivalent to 140 cm³. The mass of ethanol is calculated by multiplying the density by the volume.
mass = (140 cm³)(0.789 g/cm³)
mass = 110.46 g
Then, calculate the number of moles of ethanol by dividing the mass by the molar mass of ethanol equal to 46.07 g/mol.
number of moles = (110.46 g/ 46.07 g/mol) = 2.4 mol
Then, multiply the number of moles by the Avogadro's number.
2.4 mol (6.022 x 10²³)
<em> number of molecules = 1.445 x 10²⁴</em>
B. 0.937 atm
The total pressure of a gas mixture is simply the sum of the partial pressures of each gas within the mixture. So let's add them together: 0.875 atm + 0.0553 atm + 0.00652 atm = 0.93682 atm.
Since we only have 3 significant figures in our data, round the result to 3 figures, giving 0.937 atm, which exactly matches option "B" which is the correct answer.
C the answer is cesium, study's show that it has the lowest ionization out of all elements. Hope this helped!
It says on google
<span>An acid-base indicator (e.g., phenolphthalein) changes color depending on the pH. Redox indicators are also frequently used. A drop of indicator solution is added to the titration at the start; when the color changes the endpoint has been reached, this is an approximation of the equivalence point.</span>
Cu ions reduced to cu and Al oxidized to Al ions is the answer. copper ions is right hand side of the E.M.F cell where reduction take place and is reduced to copper metal. Al metal is at left hand side of the E.m.f cell where oxidation take place and is oxidized to Al ions
