Answer:- 0.143 M
Solution:- HCl and NaOH reacts in 1:1 mol ratio as shown in the below reaction:

Let's calculate the initial moles of HCl and the moles of NaOH added to it:

= 0.075 mol HCl

= 0.025 mol NaOH
Since they react in 1:1 mol ratio, 0.025 mol of NaOH will react with 0.025 moles of HCl.
Remaining moles of HCl = 0.075 - 0.025 = 0.050
Total volume of the resulting solution = 0.250 L + 0.100 L = 0.350 L
So, the concentration of HCl in the resulting solution = 
= 0.143 M
Hence, the concentration of HCl acid in the resulting solution is 0.143 M.
Answer:
Ductility
Explanation:
Ductility is the ability of a metal to be converted into a thin wire without getting break and loosing its hardness. The property of Ductility of a metal allows us to make a wider use of them. Some most ductile metals are gold, silver, copper etc. whereas some of the metals with very less ductility are tungsten, steel and other alloys as they are very hard to transform into a thin wire.
A metal with less ductility can be malleable as it can have the ability to be converted into a thin sheet. Not all the metals are ductile but some of them have high ductility, some have less and some of them are non ductile.
Density=mass/volume
1.118=1.75/volume
1.118xvol=1.75
volume=1.75/1.118
volume=1.57ml