The number of mole of Ca reacted is:
4.86 g Ca/ (40.08 g/mol Ca)= 0.121 mol Ca
Because Ca reacted completely with oxygen and there is 2 mol Ca, there is 1 mol O2 reacted.
Total mass of oxygen that reacted is:
0.121 mol Ca* (1mol O2/ 2 mol Ca)* (32 g O2/ 1 mol O2)= 1.94 g O2 reacted.
Hope this would help~
Volume = (4/3) × π × r^3
R = 1/2 D
R = 7
V = 4/3 x π x 7^3
Exact Form:
1372 π/ 3
Decimal Form:
1436.75504024
Answer:
43.89 min
Explanation:
Given that:-
The speed of light = 
The distance = 
The conversion of distance in km to distance into m is shown below as:-
1 km = 1000 m
So,
Distance = 
The relation between speed distance and time is shown below as:-

Thus,


Time = 2633.33 seconds
Also, 1 s = 1/60 min
So,
Time=
Answer:
B. Cu + 4HNO3 → Cu(NO3)2 + 2H2O + 2NO2
Explanation:
Hello,
In this case, we should understand oxidizing agents as those substances able to increase the oxidation state of another substance, therefore, in B. reaction we notice that copper oxidation state at the beginning is zero (no bonds are formed) and once it reacts with nitric acid, its oxidation states raises to +2 in copper (II) nitrate, thus, in B. Cu + 4HNO3 → Cu(NO3)2 + 2H2O + 2NO2 nitritc acid is acting as the oxidizing agent.
Moreover, in the other reactions, copper (A.), sodium (C. and D.) remain with the same initial oxidation state, +2 and +1 respectively.
Regards.