Answer: The balanced equation is
Au(s) + 3HNO3(aq) + 4HCl(aq) ---> HAuCl4(aq) + 3NO2(g) +3H2O(l)
The function of HCl in a solution of Aqua regia, that is used to dissolve gold is to dissolve other metals like quartz or iron stone that surround the gold.
Explanation: To balance the equation, we check the ratio of each element in the reacting side and the product side ( left and right hand side). Let their ratio be equal be adding moles to the compound of the element or the element it's self in either side of the equation.
HCl which is called hydrochloric acid, is an acid that does not react with gold, but it react with every other substance, like your skin, metals etc. it is used to clean a gold, by dipping the gold inside it, all the metals on the surface of the gold will dissolve.
When dissolving a gold in aqua regia solution, HCL is added to prepare this solution because it will help to dissolve all other substance on the surface of the gold.
C. Single-replacement
Chlorine replaces Bromine in KBr.
Answer:
The atomic radius of calcium is approximately 175
Explanation:
Given that the atomic radius of magnesium = 150 pm
The atomic radius of strontium = 200 pm
Therefore, given that calcium comes in between magnesium and strontium in group 2 of the periodic table, the atomic radius should be half way between the length of the atomic radius of magnesium and strontium, given that the atomic radius is not a fixed quantity
Therefore;
The atomic radius of calcium is approximately given as follows;
The approximate atomic radius (200 + 150)/2 = 175 pm.
The answer:
<span>The equation of its dissolution in water is: AgNO3 → Ag + (aq) + NO3- (aq)
and </span>AgNO3 → Ag + (aq) + NO3- (aq)
1 mol 1mol 1mol
? -------- 0.854mo
so for finding the value, it is sufficients to complute 1 x 0.854 mol =0.854 mol
so, 0.854 mol is required for the reaction to form 0.854 mol of Ag
1.Hans and Zacharias Janssen created the first microscope.
2.Robert Hooke was the first to use the word “cell.”
3.Anton van Leeuwenhoek observed small organisms he called “animalcules.”
4.Matthias Schleiden theorized that plants are made of cells.
5.Theodor Schwann theorized that animals are made of cells.
6.Rudolf Virchow theorized that cells come from other pre-existing cells.