Answer:
i) 16.5g of ZnO
ii) 9.8 dm³ of NO2
Explanation:
The working is shown in the photo so kindly refer to it
Flammability is a chemical change because when you burn something, it no longer has the same properties.
Answer:
14,448 J of heat would it take to completely vaporize 172 g of this liquid at its boiling point.
Explanation:
The heat Q that is necessary to provide for a mass m of a certain substance to change phase is equal to Q = m*L, where L is called the latent heat of the substance and depends on the type of phase change.
During the evaporation process, a substance goes from a liquid to a gaseous state and needs to absorb a certain amount of heat from its immediate surroundings, which results in its cooling. The heat absorbed is called the heat of vaporization.
So, it is called "heat of vaporization", the energy required to change 1 gram of substance from a liquid state to a gaseous state at the boiling point.
In this case, being:
- L= 84

and replacing in the expression Q = m*L you get:
Q=172 g*84 
Q=14,448 J
<u><em>14,448 J of heat would it take to completely vaporize 172 g of this liquid at its boiling point.</em></u>
Answer : The reaction is endothermic.
Explanation :
Formula used :

where,
= change in temperature = 
Q = heat involved in the dissolution of KCl = ?
m = mass = 0.500 + 50.0 = 50.5 g
c = specific heat of resulting solution = 
Now put all the given value in the above formula, we get:


The heat involved in the dissolution of KCl is positive that means as the change in temperature decreases then the reaction is endothermic and as the change in temperature increases then the reaction is exothermic.
Hence, the reaction is endothermic.
Explanation:
It is given that, the Average Speed of the orbiting space shuttle is 17500 miles/hour.
We need to convert the speed in kilometers/
second
We know that,
1 mile = 1.609 km
or
1 km = 0.621 miles
1 hour = 3600 seconds

Now cancel the miles in numerator.

So, 17500 miles/hour is equal to 7.82 km/s.