Counting gives an exact number and exact numbers have infinite sig figs.
Answer: 
Explanation:-
Single replacement reaction is a chemical reaction in which more reactive element displaces the less reactive element from its salt solution.
As zinc is more reactive than copper, it could easily displace copper from its aqueous solution and thus leads to formation of zinc (II) sulfate and pure copper.
The chemical reaction can be represented as :

The phases are represented as (s) for solid sate, (l) for liquid state, (g) for gaseous state and (aq) for aqueous state.
Only the Fe is unbalanced.
:)
A covalent bond describes two atoms (most likely nonmetals) that share their valence electrons to satisfy the octet rule. Carbon and oxygen are both nonmetals, and they would share electrons with each other through a bond that is not polar enough to be considered ionic. The answer should be B
Answer: The molar mass of the gas is 31.6 g/mol
Explanation:
According to ideal gas equation:
P = pressure of gas = 3.0 atm
V = Volume of gas = 25.0 L
n = number of moles = ?
R = gas constant =
T =temperature =
Moles =


The molar mass of the gas is 31.6 g/mol