Subtract the ratio of the actual mass of the compound to the empirical formula mass from the subscripts of the empirical formula.
Divide the ratio of the actual mass of the compound to the empirical formula mass by the subscripts of the empirical formula.
Add the ratio of the actual mass of the compound to the empirical formula mass to the subscripts of the empirical formula.
Answer : Option A) Multiply the ratio of the actual mass of the compound to the empirical formula mass by the subscripts of the empirical formula.
Explanation : To find molecular formula for a compound one needs to follow the below steps using the emphirical formula of that compound.
Step 1) Calculate the empirical formula mass of that compound
Step 2) Take the ratio of gram molecular mass by the empirical formula mass that was obtained in step 1.
Step 3) Multiply each of the subscripts within the empirical formula by the number that is calculated in step 2.
By following these easy steps one can find the molecular formula.
The step that would help a student finds the molecular formula of a compound from the empirical formula is by ‘Multiply the ratio of the actual mass of the compound to the empirical formula mass by the subscripts of the empirical formula.’
Fill the blanks
Answer:
Explanation:
In ions, protons are never taken or given. Only the number of electrons are changed
Br^1- gains 1 electron, so the number of electrons increases from 35 to 36. No protons are taken away, to the number of protons and the atomic number of Br1- is still 35, and the number of neutrons is still 45.
Answer: Therefore, the molar mass of the unknown substance is 68.4 g/mol.
Explanation: We can use the freezing point depression equation to solve for the molar mass of the unknown substance:
ΔT = Kf × m
where ΔT is the change in freezing point, Kf is the freezing point depression constant of the solvent (naphthalene), and m is the molality of the solution.
First, we need to calculate the molality of the solution:
molality = moles of solute / mass of solvent (in kg)
We don't know the number of moles of the unknown substance, but we can assume that the naphthalene does not contribute significantly to the total mass of the solution (since its mass is much smaller than the mass of the unknown substance). Therefore, we can use the entire mass of the solution (1000g + 12.3g = 1012.3g) as the mass of solvent.
mass of solute = 1000g
mass of solvent = 12.3g
mass of solution = 1012.3g
molality = (1000g / molar mass) / (12.3g / 1000g) = 81.3 / molar mass
Next, we need to calculate the change in freezing point:
ΔT = 1.2∘C
Finally, we can use the freezing point depression constant of naphthalene to solve for the molar mass of the unknown substance:
Kf for naphthalene = 6.8∘C/m
ΔT = Kf × m
1.2 = 6.8 × (81.3 / molar mass)
molar mass = 68.4 g/mol
Therefore, the molar mass of the unknown substance is 68.4 g/mol.
What are two properties of most nonmetals? The two properties of most nonmetals are high ionization energy and poor electrical conductivity. The answer is number 1. The rest of the choices do not answer the question above.