Answer: 28.4 g of aluminum oxide is produced by the reaction of 15.0 g of aluminum metal
Explanation:
To calculate the moles :
The balanced chemical equuation is:
According to stoichiometry :
4 moles of 
produce == 2 moles of 
Thus 0.556 moles of will produce=
of
Mass of 
Thus 28.4 g of aluminum oxide is produced by the reaction of 15.0 g of aluminum metal.
Answer:
D. In both, vibrations occur in a parallel direction to the direction of the wave.
Explanation:
It is not true that in both mechanical and electromagnetic waves, vibrations occur in parallel direction to the direction of the wave.
As with all waves, they are disturbances that transfers energy without moving the materials of the medium.
- Electromagnetic waves have only one way of propagation which is a vibration in both parallel and longitudinal direction.
- Mechanical waves can be propagated either in a parallel direction or longitudinal direction and not both.
Answer:
2835 J
Explanation:
Take the specific heat capacity of water as 4.2 J/ g°C.
Energy (heat) = mass x specific heat capacity x change in temperature
(E= mcΔT)
E = 27 x 4.2 x (45-20)
E = 2835 J
