<span> First you need to know how many isotopes there are of silicon, and its average atomic units (look at periodic table). Then make up a system of equations to solve for it. Theres 3 stable silicon isotopes (28, 29, 30) so you will need to have 3 equations. You must be given the percent abundance of at least one of the isotopes to solve because here I can only see 2 equations (numbered down below) set x = percent abundance of si-28 y = percent abundance of si-29 z = percent abundance of si-30 since all of silicon atoms account for 100% of all silicon: x + y + z = 100% = 1 therefore: 1) x = 1 - y - z You also have 2) 28x + 29y + 30z = average atomic mass you can substitute x so that equation becomes: 28 (1 - y - z) + 29y + 30z = average atomic mass See how you have 2 variables here? You cant go on until you know the value of one isotope already or you have given a clue which you can derive the third equation</span>
Answer: The boiling point of a 3.70 m solution of phenol in benzene is 
Explanation:
Elevation in boiling point:
where,
= change in boiling point
i= vant hoff factor = 1 (for benzene which is a non electrolyte )
= boiling point constant = 
m = molality = 3.70
Thus the boiling point of a 3.70 m solution of phenol in benzene is
Explanation:
hope it make sense to u :)
Answer:
Moles of sodium = 15.0⋅g22.99⋅g⋅mol−1 = 0.652⋅mol . Given the stoichiometry of the reaction, clearly 0.652⋅mol sodium hydroxide will result.
Explanation:
please mark me
Answer:
345.44 g or 0.34544 kg
Explanation:
Applying
D = m/V...................... Equation 1
Where D = Density of mercury, m = mass of mercury, V = Volume of mercury.
make m the subject of the equation
m = D×V................. Equation 2
From the question,
Given: D = 13.6 g/mL = 13.6 g/cm³, V = 25.4 cm³
Substitute these values into equation 2
m = 13.6×25.4
m = 345.44 g
m = 0.34544 kg
Hence the mass of mercury is 345.44 g or 0.34544 kg
