Answer:
b is the anwer
Explanation:
the option is the explanation
Answer:- 448 mL of hydrogen gas are formed.
Solution:- It asks to calculate the volume of hydrogen gas formed in milliliters at STP when 0.020 moles of magnesium reacts with excess HCl acid. The balanced equation is:

There is 1:1 mol ratio between Mg and hydrogen gas. So, the moles of hydrogen gas is also equals to the moles of Mg reacted.
moles of Hydrogen gas formed = 0.020 mol
At STP, volume of 1 mol of the gas is 22.4 L. We need to calculate the volume of 0.02 moles of hydrogen gas.

= 0.448 L
They want answer in mL. So, let's convert L to mL using the conversion formula, 1L = 1000mL

= 448 mL
So, 0.020 moles of magnesium would produce 448 mL of hydrogen gas at STP on reacting with excess of HCl acid.
Answer:
D metallic
Explanation:
The chemical bonding which rises from electrostatic attractive force between the conduction electrons and the positively charged metal ions is called metallic bonding.
<u>It is sharing of the free electrons among the structure of the positively charged ions which are known as cations.
</u>
<u>In this type of bonding, these free electrons freely move in the crystal mattice of the metal. </u>
The bonding accounts for properties of metals, such as ductility, strength, electrical and thermal conductivity and resistivity and luster.
Answer is
C. 2.07 M
For explanation
M1V1 = M2V2
M2 = (M1V1)/V2
M2 = (1.5M x 345ml) / 250 ml
:. M2 = 2.07 M