Answer:
12.8seconds, 14.6seconds, 16.4seconds
Explanation:
the answers should b right as long as it is increasing in trend.
the reason why is bc of lower vol of hcl, and higher vol of water present. there is amount of hcl molecules present per volume. lesser chance of collisions, lower rate of successful collisions to poduce CO2
<span>A 50-gram sample with a half-life of 12 days will have a remaining mass of 25 grams after its 12-day half-life.
Every cycle of a half-life, the sample will lose half of its mass, so if the half-life, itself, is 12 days and the time period passing is 12 days, one half-life has passed and the material will be halved.</span>
Calcium ions have oxidation state 2+ => Ca (2+).
Bromime ions (bromide) have oxidation state 1- => Br (-).
So, to be neutral the compound has to have two Br (-) ions per each Ca(2+) ion.
That is represented in the chemical formula as Ca Br2, where the number 2 to the right of Br is a subscript meaning that there are two atoms of Br per each atom of Ca (the lack of subscript means 1 atom).
Answer: Ca Br2.
1. Answer;
Copper (ii) carbonate.
The name of the compound CuCO3 is copper (ii) carbonate.
Explanation;
Cu is the chemical symbol for the copper and CO3 is the chemical symbol for the carbonate group and each one of them has valency of two. Therefore, a compound CuCO3 is formed.
2. Answer;
Yes
Ca2+ reacted with Na2S to form CaS and Na+
Explanation:
Calcium ions reacts with sodium sulfide to form calcium sulfide and sodium ions.
For example; a salt of calcium, calcium carbonate reacts with sodium sulfide to form sodium carbonate and calcium sulfide.
3. Answer;
NaCl and Ag+ do not form a product
Explanation;
The reaction between sodium chloride and silver metal will not take place. This is because silver (Ag) is less reactive than sodium metal and therefore cannot displace sodium from its salt. In other words, silver metal is lower in the reactivity series as compared to sodium metal which indicates sodium metal is more reactive than silver.
4. Answer;
Formation of a white precipitate ; this indicates that silver sulfide is insoluble in water.
Explanation;
When an aqueous solution containing Ag+ ions is added to aqueous solution of sodium sulfide (Na2S), there will be formation of white precipitate. Formation of white precipitate indicates that a reaction has taken place to form a water insoluble compound. The water insoluble compound occurs as a precipitate. The white precipitate is silver sulfide (Ag2S)
2 Ag+ (aq) + Na2S(aq) ----- Ag2S (s) + 2 Na+ (aq)
Answer:
Percent loss of water = 25%
Explanation:
Given data:
Mass of hydrated salt = 15.6 g
Mass of anhydrous salt = 11.7 g
Percentage of water lost = ?
Solution:
First of all we will calculate the mass of water in hydrated salt.
Mass of water = Mass of hydrated salt - Mass of anhydrous salt
Mass of water = 15.6 g - 11.7 g
Mass of water = 3.9 g
Now we will calculate the percentage.
Percent loss of water = mass of water / total mass × 100
Percent loss of water = 3.9 g/ 15.6 g × 100
Percent loss of water = 25%
