Answer:
An open system is :-
B. A system that allows energy and mass to move in and out of it.
Example :-
Water boiling in a pot on a stove. (Without lid).
Answer:
<em>The correct option is the structure in the option D. </em>
Explanation:
Ammonia contains a single nitrogen atom bonded to three hydrogen atoms.
The structure present in option A shows a single nitrogen atom bonded with a single hydrogen atom hence it is not correct.
The structure in option B shows a nitrogen atom bonded to four hydrogen atoms hence it is also not correct.
The structure in option C shows a nitrogen atom bonded to two hydrogen atoms hence it is also not correct.
The structure in option D shows a nitrogen atom bonded to three hydrogen atoms which is the correct structure of ammonia (NH3).
Answer:
1. 0.45 mole
2. 49.95g
Explanation:
The following were obtained from the question:
Volume of solution = 300mL = 300/1000 = 0.3L
Molarity = 1.5 M
Mole of CaCl2 =?
1. We can obtain the mole of the solute as follow:
Molarity = mole of solute /Volume of solution
1.5 = mole of solute/0.3
Mole of solute = 1.5 x 0.3
Mole of solute = 0.45 mole
2. The grams in 0.45 mole of CaCl2 can be obtained as follow:
Molar Mass of CaCl2 = 40 + (35.5 x 2) = 40 + 71 = 111g/mol
Mole of CaCl2 = 0.45 mole
Mass of CaCl2 =?
Mass = number of mole x molar Mass
Mass of CaCl2 = 0.45 x 111
Mass of CaCl2 = 49.95g
Key word is “halo”, as in “halogens”. The halogens are group 7 on the periodic table, which includes Florine, Chlorine, Bromine, and Iodine
Answer is 4.
