Answer:
the percentage by mass of Nickel(II) iodide = 23.58%
Explanation:
% by mass of solute = (mass of solute/mass of solution) x 100%
% by mass of NiI2 = (mass of NiI2/mass of solution) x 100%
% by mass of NiI2 = (5.47 grams/23.2 grams) x 100% = 23.58% m/m
Answer: There are
molecules present in 7.62 L of
at
and 722 torr.
Explanation:
Given : Volume = 7.62 L
Temperature = 
Pressure = 722 torr
1 torr = 0.00131579
Converting torr into atm as follows.

Therefore, using the ideal gas equation the number of moles are calculated as follows.
PV = nRT
where,
P = pressure
V = volume
n = number of moles
R = gas constant = 0.0821 L atm/mol K
T = temperature
Substitute the values into above formula as follows.

According to the mole concept, 1 mole of every substance contains
atoms. Hence, number of atoms or molecules present in 0.244 mol are calculated as follows.

Thus, we can conclude that there are
molecules present in 7.62 L of
at
and 722 torr.
It does not affect the mass, it only affects the outwards appearance of the ice/water.
Answer:
CH3COCH3
Explanation:
Acetone is an organic compound belonging to the organic ketone function.
To recognize which function a compound belongs to, we must analyze its functional group. For example, hydroxyl (OH) is characteristic of alcohols. For ketones, the functional group is carbonyl, which is represented below.
Analyzing the options, we can notice that NH3, HNO3, KClO2 and H3PO3 are inorganic compunds, because they don't have carbon in their structures. KOH has the hydroxyl, so it's a alchol, and CH3COCH3 may be writing as a ketone.
Answer: Change in a single nitrogen base in the DNA sequence will not have any significant effect on the organism.
So A
Explanation:
This is known as point mutation and it does not have any significant change in the protein and it is least harmful type of DNA mutation.