Answer: The final temperature of both substances at thermal equilibrium is 301.0 K
Explanation:

As we know that,

.................(1)
where,
q = heat absorbed or released
= mass of gold = 31.5 g
= mass of water = 63.4 g
= final temperature = ?
= temperature of gold = 
= temperature of water = 
= specific heat of gold = 
= specific heat of water= 
Now put all the given values in equation (1), we get
![-31.5\times 0.129\times (T_{final}-342.4)=[63.4\times 4.184\times (T_{final}-300.4)]](https://tex.z-dn.net/?f=-31.5%5Ctimes%200.129%5Ctimes%20%28T_%7Bfinal%7D-342.4%29%3D%5B63.4%5Ctimes%204.184%5Ctimes%20%28T_%7Bfinal%7D-300.4%29%5D)

The final temperature of both substances at thermal equilibrium is 301.0 K
Answer:
I think it might be elements and compounds! I may be wrong though.
Less than the revolution perilous around earth
The mass of Al metal that releases 2.4 L of hydrogen gas at STP is calculated as below
AT STP 1 mole =22.4 l
what about 22.4l =? moles
(22.4 L x 1 mole) /22.4 L= 2mole
write the reacing reaction
2Al+ 6 HCL = 2AlCl3 + 3H2
by use of mole ratio between Al to H2 which is 2 : 3 the mole Al = 1 x2/3 = 0.667 moles
mass =moles x molar mass
=0.667 mole x27 g/mol= 18 grams
Answer: 2.35 (no unit given)
Explanation: