Answer:
A
Explanation:
The group number of an element is equal to the number of electrons the outermost shell (or highest energy level) contains
Balanced Eqn
2
C
2
H
6
+
7
O
2
=
4
C
O
2
+
6
H
2
O
By the Balanced eqn
60g ethane requires 7x32= 224g oxygen
here ethane is in excess.oxygen will be fully consumed
hence
300g oxygen will consume
60
⋅
300
224
=
80.36
g
ethane
leaving (270-80.36)= 189.64 g ethane.
By the Balanced eqn
60g ethane produces 4x44 g CO2
hence amount of CO2 produced =
4
⋅
44
⋅
80.36
60
=
235.72
g
and its no. of moles will be
235.72
44
=5.36 where 44 is the molar mass of Carbon dioxide
hope this helps
Answer:
B
Explanation:
Applying law of electrostatic which states that like charges repel each other and unlike charges attract each other
N and S are unlike charges that turn and make the former repulsive force (due to two like charges N and N)to <em>reduce</em> and attractive force between N and S to <em>increa</em><em>se</em>
Answer: Option (B) is the correct answer.
Explanation:
Marble is also known as calcium carbonate and its chemical formula is
.
When it combines with vinegar then it results in the formation of calcium acetate which is a water soluble compound along with the release of carbon dioxide which occurs in the form of bubbles and water.
The reaction is as follows.

Whereas vinegar being a weak acid will not react with glass, copper and steel.
D. Cell membrane: surrounds a cell and allows substances to pass in and out