Answer: CaCO3 = CaO + CO2
Explanation:
CaCO3 = CaO + CO2
This is balanced already.
<u> Elem </u> <u>Reactant</u> <u>Products</u>
Ca 1 1
C 1 1
O 3 3
Answer: 3.97 moles HCl
Explanation: Solution:
2.39x10²⁴ atoms HCl x 1 mole HCl /
6.022x10²³ atoms HCl
= 3.97 moles HCl
<u>Answer:</u> The amount of calcium hydroxide needed to react is 2.04 moles
<u>Explanation:</u>
We are given:
Moles of phosphoric acid = 1.36 moles
For the given chemical equation:

By Stoichiometry of the reaction:
2 moles of phosphoric acid reacts with 3 moles of calcium hydroxide
So, 1.36 moles of phosphoric acid will react with =
of calcium hydroxide
Hence, the amount of calcium hydroxide needed to react is 2.04 moles
True becuase the substance changed into another substance which is a example of a chemical reaction.
Answer:
Sulfur: -1
Carbon: 0
Nitrogen: 0
Explanation:
The thiocyanate ion SCN- can have only two resonance structures, which are:
S - C ≡ N <--------> S = C = N
In the first structure, we have one single bond and one triple bond, in this case, the negative charge is located in the sulfur. This is because Sulfur have 6 electrons and those electrons are present in the atom, (see picture below), and counting the electron that is sharing with the Carbon, the total electrons that sulfur has is 7 (It has one more than usual). Carbon and nitrogen are already stable with 0 of formal charge, because carbon can only have 4 electrons which 1 is sharing with sulfur and the other 3 with the nitrogen, and nitrogen have 5 electrons, three sharing with carbon and the other two kept it for itself.
In the second structure, the negative charge of the sulfur is transfered to the nitrogen, meaning that it has 6 electrons the nitrogen (formal charge -1) and carbon and sulfur with 4 and 6 electrons respectively.
Between these two structures, the most stable is the first one basically because Sulfur is a better nucleophile than the Nitrogen, and can form stronger hydrogen bond in acid, giving more stable structure.