Chemical change because it cannot be reversed
Answer:
What mass (g) of barium iodide is contained in 188 mL of a barium iodide solution that has an iodide ion concentration of 0.532 M?
A) 19.6
B) 39.1
C) 19,600
D) 39,100
E) 276
The correct answer to the question is
B) 39.1 grams
Explanation:
To solve the question
The molarity ratio is given by
188 ml of 0.532 M solution of iodide.
Therefore we have number of moles = 0.188 × 0.532 M = 0.100016 Moles
To find the mass, we note that the Number of moles =
from which we have
Mass = Number of moles × molar mass
Where the molar mass of Barium Iodide = 391.136 g/mol
= 0.100016 moles ×391.136 g/mol = 39.12 g
Answer:
Explanation:
An element with atomic number 18 is a noble gas.
The element with atomic number 19 will have one extra electron so it can donate one electron or shed one electron to attain noble gas configuration .
It tends to shed one electron to become positively charged ion . Hence they are electro-positive elements .
Similarly the element with atomic number 17 will have one short electron so it can gain one electron to attain noble gas configuration .
They tend to gain one electron to become negatively charged ion . Hence they are electro-negative elements . They have high electronegativity .
Answer:

Explanation:
Combination reactions are the reactions in which two or more atoms/ molecules combine to give a single product.
Aluminum metal combines with iodine to given aluminium iodide.
Aluminium has a valency of 3 and iodine has valency of 1, so the formula is 
The reaction is shown below as:

You need to use the equation PV = nRT
The only “trick” in these problems is you need to use the correct UNITS. Especially for the “R” value.
If you get the units (eg temps in Celsius or Kelvin) corresponding to the correct “matching” units of the other variables.
You need to convert the temp into Kelvin first