Answer:- 
Explanations:- The first reaction is combustion reaction as the hydrocarbon is burned in presence of oxygen to give carbon dioxide and water.
Second reaction is the synthesis reaction as in general a synthesis reaction looks like:

Third reaction is the decomposition reaction as it looks opposite of synthesis reaction.

In general, a single displacement reaction looks like:

Fourth reaction is single replacement reaction as bromine is replaced by chlorine.
So, the correct choice is the last reaction,
.
The given question is incomplete. The complete question is:
How much heat is produced when 24.8 g of
is burned in excess oxygen gas
Given:
ΔH= −802 kJ.
Answer: 1243.1 kJ
Explanation:
Heat of combustion is the amount of heat released on complete combustion of 1 mole of substance.
Given :
Amount of heat released on combustion of 1 mole of methane = 802 kJ kJ/mol
According to avogadro's law, 1 mole of every substance occupies 22.4 L at NTP, weighs equal to the molecular mass and contains avogadro's number
of particles.
1 mole of
weighs = 16 g
Thus we can say:
16 g of
on combustion releases heat = 802 kJ
Thus 24.8 g of
on combustion releases =
Thus heat released when 24.8 g of methane is burned in excess oxygen gas is 1243.1 kJ
The rover was designed to explore A.Mars
Answer
:
2. Hydrogen forms bonds through the overlap of 1s atomic orbitals and the sharing of electrons between atoms. Carbon forms bonds through the overlapping of sp hybrid atomic orbitals and the sharing of electrons between carbon atoms.
Explanation:
The H-H bond is formed by the overlap of two 1s orbitals and the sharing of electrons between the two atoms.
A carbon atom must use the overlap of hybridized atomic orbitals and the sharing of electrons to bond with another carbon atoms.
1. is <em>wrong</em> because H can use only its <em>1s orbital</em> for bonding.
3. is <em>wrong</em> because C must <em>share electrons</em> to form a carbon-carbon bond.
4. is <em>wrong</em> because <em>C does NOT use overlapping of 2s orbitals</em> for bonding. It uses the overlap of hybridized orbitals.
5. is <em>wrong</em> because H must <em>share electrons</em> to form an H-H bond.