Answer:
The two statements are all True for group 7 and 8 elements.
Explanation:
The Group 7 elements are known as the halogens. They are reactive non-metals and are always found in compounds with other elements. Chlorine, bromine and iodine are all halogens.
Chlorine, bromine and iodine are the three common Group 7 elements. Group 7 elements form salts when they react with metals. The term ‘halogen’ means 'salt former'.
In addition to the discription given to norble gases in the question which is true, norble gases;
- are inert gases located on the right of the periodic table.
- have a full-set of valence electrons, so they're stable, unreactive
- are colorless, odorless and tasteless.
- have low melting and low boiling points.
- can be found in small amounts in the Earth's crust and the Earth's atmosphere.
Answer:
Option A. FeCl3
Explanation:
The following data were obtained from the question:
Mass of iron (Fe) = 6.25g
Mass of the compound formed = 18g
From the question, we were told that the compound formed contains chlorine. Therefore the mass of chlorine is obtained as follow
Mass of chlorine (Cl) = Mass of compound formed – Mass of iron.
Mass of chlorine (Cl) = 18 – 6.25
Mass of chlorine (Cl) = 11.75g
The compound therefore contains:
Iron (Fe) = 6.25g
Chlorine (Cl) = 11.75g
The empirical formula for the compound can be obtained by doing the following:
Step 1:
Divide by their molar mass
Fe = 6.25/56 = 0.112
Cl = 11.75/35.5 = 0.331
Step 2:
Divide by the smallest
Fe = 0.112/0.112 = 1
Cl = 0.331/0.112 = 3
The empirical formula for the compound is FeCl3
Answer:
The volume of water needed to recrystallize 0.700 g of benzoic acid is 10.29 mL.
Explanation:
For the complete recrystalization,
the amount of hot water should be such that, the benzoic acid is completely soluble in it.
As we are given that the solubility of benzoic acid in hot water is 68.0 g/L. Now we have to determine the volume of water is needed to recrystallize 0.700 g of benzoic acid.
we conclude that,
As, 68.0 grams of benzoic acid soluble in 1 L of water.
So, 0.700 grams of benzoic acid soluble in of water.
The volume of water needed = 0.01029 L = 10.29 mL
conversion used : (1 L = 1000 mL)
Therefore, the volume of water needed to recrystallize 0.700 g of benzoic acid is 10.29 mL.
6000 I pretty sure tell me if it's right
