Answer:
Alkali metal hydroxides can be used to test the identity of metals in certain salts. The colour of the precipitate will help identify the metal : Calcium hydroxide is soluble; no precipitate is formed.
J. J. Thomson is the corect awncer
Answer:
This question is incomplete, however, the unknown compound can be inferred to be "Lithium Bromide"
Explanation:
The unknown compound firstly is said to be an ionic compound. An ionic/electrovalent compound is a compound in which it's constituent ions transfer/receive electron(s). They are mostly made of group 1 and group 7 elements. Examples include NaCl, NaF, LiF and KCl.
Also, the ion (metallic ion) that produces a red flame test colour in a flame test is the <u>Lithium ion (Li⁺).</u> Also, when dissolved in water or hexane, the only halogen that produces a red/orange colour is bromine. Hence, the unknown ionic compound can be inferred to be Lithium Bromide.
The weight in grams = 7.93 g
Given volume = 2.00
Given density = 0.242 g/
We need to find the Mass(weight) in grams.
To find the weight in grams we need to keep in mind that the volume and density must use the same volume unit for cancellation. So that the volume units will cancel out, leaving only the mass units.
The unit of given volume is
and unit of volume in density is
, so first we need to change the unit of volume from
to
so that the volume units will cancel out, leaving only the mass units.
1
= 16.39
(given conversion)

units get cancel out leaving the
unit.

Mass = Density X Volume.
Density = 0.242 g/
and Volume = 32.78 

Mass = 7.93 grams (g)