The gram-formula mass means that the mass of one mole molecule. Then you just need to calculate the elements together. So the gram-formula mass of (NH4)3PO4 is equals to (14+4)*3+31+16*4= 149g/mol. So the answer is (c)
Answer: mole fraction of methanol = 0.590
mole fraction of ethanol = 0.410
Explanation:
We are given:
Equal masses of methanol
and ethanol
are mixed.
let the mass be x g.
Calculating the moles of methanol in the solution, by using the equation:

Calculating the moles of ethanol in the solution, by using the equation:

To calculate the mole fraction of methanol, we use the equation:


To calculate the mole fraction of ethanol, we use the equation:


Thus mole fraction of methanol is 0.590 and mole fraction of ethanol 0.410 in three significant figures.
Here we have to choose the correct statement on the effect of temperature on the motion of the molecules and atoms of a gas.
As the temperature increases the molecules and atoms move faster.
As per the kinetic theory of gas molecules and atoms the kinetic energy (K.E.) of the atom or molecules is related to temperature by the equation
K.E. =
kT ( k = Boltzmann constant, T = temperature.
Thus as the temperature increases the K.E. increases thus the atom or molecules move faster.
With the decrease of temperature the movement of the atoms or molecules will be less and they will be near to each other.
The increment of temperature increase the K.E. thus the atoms or molecules move apart from each other.
With the decrease of temperature the movement of the atoms or molecules decreases.
Answer: is the benefit worth the cost?
Explanation: for those on edge :)