Answer:
a. 342.9 kJ of heat are absorbed.
Explanation:
Calculation of the moles of
as:-
Mass = 20.00 g
Molar mass of
= 17.031 g/mol
The formula for the calculation of moles is shown below:
Thus,

Given that:- 
It means that 1 mole of
undergoes reaction and absorbs 1168\ kJ of heat
So,
1168 mole of
undergoes reaction and absorbs
of heat
<u>Amount of heat absorbed = + 342.9 KJ</u>
From the equation q=mCΔT, set the q of copper = to q of water,
So --- mCΔT(copper)=mCΔT(water).
mass (Cu - copper) = 38g
mass (H2O - water) = 15g
C (H2O) = 4.184 J/g*C
ΔΤ (H2O) = 33-22 = 11*C
ΔΤ (Cu) = 33-80 = -47*C (the final temp is the same for both materials - thermal equilibrium)
C (Cu) = ?
So --- 38(-47)C[Cu]=15(4.184)(11)
--- C[Cu]=690.36/(-1786) = 0.3865 J/g*C, or 0.39 in 2 sig figs. (The negative goes away, because specific heats are usually positive)
Simple...
moving along the periodic table ---->>>
Oxygen has 6.
Nitrogen has 5.
Sodium has 1.
Neon has 8.
Thus, your answer, Oxygen.
Answer:

Explanation:
We can use the Ideal Gas Law — pV = nRT
Data:
V = 66.8 L
m = 77.8 g
T = 25 °C
Calculations:
(a) Moles of N₂

(b) Convert the temperature to kelvins
T = (25 + 273.15) K = 298.15 K
(c) Calculate the pressure
