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,
.
Answer:
b) 7
Explanation:
The pH of a solution produced by the neutralization reaction between 1M of H₂SO₄ and KOH with 1M is closest to 7.
pH is a standard for measuring the acidity and alkalinity of a solution. A solution that is acidic will have a pH less than 7, a neutral solution will have pH of 7 and a basic solution will have pH greater than 7.
What is a neutralization reaction?
- It is an acid-base reaction in which hydrogen and hydroxide ions combines to form water.
- Also a salt results from the combination of the other ions.
In this reaction a base simply neutralizes an acid and the solution becomes neutral before it goes into completion.
Therefore, a neutral solution will have pH of 7 or close to it.
Answer:
The median would be 6700
Explanation:
Arrange data values from lowest to highest value
The median is the data value in the middle of the set
.
Ordering a data set x1 ≤ x2 ≤ x3 ≤ ... ≤ xn from lowest to highest value, the median x˜ is the data point separating the upper half of the data values from the lower half.
If the size of the data set n is odd the median is the value at position p where
Formula for the median
p=n+12
x˜=xp
If n is even the median is the average of the values at positions p and p + 1 where
p=n2
x˜=xp+xp+12
If there are 2 data values in the middle the median is the mean of those 2 values.
A random person put the answer for you
I think the answer would be trenches but I’m sorry if I’m wrong