Answer:
The mass of the surrounding is 
Explanation:
From the question we are told that
The mass of
is 
The mass of water is 
The chemical equation for the dissociation process is

The specific heat capacity of the mixture is 
The combined mass of the solution is

The mass of the surround here is the mass of the coffee-cup calorimeter and this contain the mixture ( water and the NaOH ) so the mass of the surrounding is

Answer:
The Order is as follow,
C-H < S-H < H-Br < H-Cl
Explanation:
Polarity depends on the electronegativity difference between two atoms, greater the electronegativity difference, greater will be the polarity of bond and vice versa.
Electronegativity Difference between Hydrogen and other given elements are as follow,
1) C-H;
E.N of Carbon = 2.55
E.N of Hydrogen = 2.20
------------
Difference 0.35
2) S-H;
E.N of Sulfur = 2.58
E.N of Hydrogen = 2.20
------------
Difference 0.38
3) H-Br;
E.N of Bromine = 2.96
E.N of Hydrogen = 2.20
-------------
Difference 0.76
4) H-Cl;
E.N of Chlorine = 3.16
E.N of Hydrogen = 2.20
-----------
Difference 0.96
Hence it is proved that the greatest electronegativity difference is found between H and Chlorine in H-Cl, therefore it is highly polar bond and vice versa.
Answer is: 0,275 moles of oxygen are consumed.
Chemical reaction: 2Mg + O₂ → 2MgO.
n(Mg) = 0,550 mol.
n(O₂) = ?
from chemical reaction: n(Mg) : n(O₂) = 2 : 1.
0,550 mol : n(O₂) = 2 : 1.
2n(O₂) = 0,550 mol.
n(O₂) = 0,275 mol.
n - amount of substance.
When a volcano erupts magma comes from the top when the magma cools down it hardens and leaves a hard surface