I got you
The molecular formula for the combustion of butane in oxygen is:
2 C4H10 + 13 O2 ---> 8 CO2 + 10 H20
<span>You take the mass of carbon dioxide, 56.8g, divide by its molar mass, 44.01g/mol, to produce the moles of carbon dioxide. This is multiplied by the molar ratio of butane/CO2, (2/8) = 1/4, which gives the moles of butane required to produce the carbon dioxide. Multiply the number of moles of butane by its molar mass, 58.12g/mol, to produce the mass of butane. Mass of butane = 18.8g</span>
Answer:
Vapour pressure of solution is 78.151 torr
Explanation:
Molar mass of biphenyl = 154.21 g
Molar mass of benzene = 78.11 g
19.2 g biphenyl = (19.2/154.21) moles of biphenyl = 0.125 moles of biphenyl
33.7 g of benzene = (33.7/78.11) moles of benzene = 0.431 moles of benzene
Total number of moles = (0.125+0.431) moles = 0.556 moles
Mole fraction of benzene in solution = (0.431/0.556) = 0.775
According to Roults law, vapour pressure of solution made from non-volatile solute = 
Here solute is biphenyl and solvent is benzene
So, vapour pressure of solution = 
= 78.151 torr
Answer:
D) atomic radii increase from top to bottom of a group
Explanation:
Atomic radii trend along group:
As we move down the group atomic radii increased with increase of atomic number. The addition of electron in next level cause the atomic radii to increased. The hold of nucleus on valance shell become weaker because of shielding of electrons thus size of atom increased.
As the size of atom increases the ionization energy from top to bottom also decreases because it becomes easier to remove the electron because of less nuclear attraction and as more electrons are added the outer electrons becomes more shielded and away from nucleus.
Other options are incorrect because,
A) atomic radii increase from left to right across the period
Correct = atomic radii decreases from left to right across the period
B) ionization energy increases from top to bottom within a family
Correct = ionization energy decreases from top to bottom within a family
C) electronegativity decreases from left to right across a period
Correct = electronegativity increases from left to right across a period
