Answer:
the open bag allowed the gas from the reaction to escape
Answer:
Grey precipitate implies the presence of silver ions
Yellow precipitate implies the presence of lead II ions
Explanation:
Qualitative analysis provides us a quick method of identifying ions present in a sample by chemical reactions involving simple reagents. Precipitates having a unique colour is formed. The identity of ions in the sample is deduced from the colour of precipitate obtained when particular reagents are added.
In the question, a precipitate containing silver ions upon standing turn into grey colour. Similarly, lead II ions give a yellow precipitate.
Answer: Its average atomic mass is 114.9 amu
Explanation:
Mass of isotope 1 = 113 amu
% abundance of isotope 1 = 5% = 
Mass of isotope 2 = 115 amu
% abundance of isotope 2 = 95% = 
Formula used for average atomic mass of an element :

![A=\sum[(113\times 0.05)+(115\times 0.95)]](https://tex.z-dn.net/?f=A%3D%5Csum%5B%28113%5Ctimes%200.05%29%2B%28115%5Ctimes%200.95%29%5D)

Thus its average atomic mass is 114.9 amu
Answer:
When liquid water reaches the freezing point, it expands. After placing a sealed glass container full of water into the freezer, we might expect it to freeze, expand, and either crack or shatter the glass.
Explanation:
The element cobalt can form compounds in two different oxidation states, +2 and +3.
The +2 state is more common.
The ion Co2+ (aq) is pink.
Other compounds of cobalt(II), which include both anhydrous Co2+ and complex ions, are commonly blue.
If an aqueous solution contains both cobalt(II) and chloride ions, the blue ion CoCl42- forms, in equilibrium with the pink Co2+ (aq) ion.
<span>CoCl42- (aq) <===========> Co2+ (aq) + 4Cl1-(aq)</span>