Answer:
0.082g
Explanation:
The following data were obtained from the question:
Heat (Q) = 0.092J
Change in temperature (ΔT) = 0.267°C
Specific heat capacity (C) of water = 4.184J/g°C
Mass (M) =..?
Thus, the mass of present can be obtained as follow:
Q = MCΔT
0.092 = M x 4.184 x 0.267
Divide both side by 4.184 x 0.267
M = 0.092 / (4.184 x 0.267)
M = 0.082g
Therefore, mass of water was present is 0.082.
Answer:
B. They are dimensionless ratios of the actual concentration or pressure divided by standard state concentration, which is 1 M for solutions and 1 bar for gases.
Explanation:
Activity of a substance is defined as the ratio of an effective concentration or an effective pressure to a standard state pressure or a standard state pressure. It is usually a unit less ratio.
Concentrations in an equilibrium constant are really dimensionless ratios of actual concentrations divided by standard state concentrations. Since standard states are 1 M for solutes, 1 bar for gases, and pure substances for solids and liquids, these are the units to be used.
Hence, activity is a fudge factor to ideal solutions that correct the true concentration. Activity of a gas and solute concentration is a ratio with no unit.
question 1
moles = mass/molar mass of Al(OH)3
convert Kg to g
that is 1.09 x 1000=1090g
moles is therefore=1090g/78(molar mass of Al(OH)3)= 13.974 moles
question 2
moles=2.55g/327.2(molar mass of Pb(CO3)2= 7.79 x 10^-3 moles
from avogadro constant
1moles=6.02 x10^23 formula units
what about 7.79 x 10 ^-3
={(7.79 x 10^-3)moles x ( 6.02 x10^23)} /1 mole=4.69 x10^21 formula units
the answer is O reputation hope this helps did this before
