So there are 2 N, 9 H, 1 P and 4 O. so N:H:P:O is 2:9:1:4? i think
Answer:
B. adding heat to the system and having the system do work on the surroundings
Explanation:
The internal energy of a system is the energy contained within the system. From first law of thermodynamics we have the equation : dq=du+dw
and we know that energy can neither be created nor destroyed; energy can only be transferred or changed from one form to another therefore du is zero. dq = dw this means that the entire heat supplied is converted into work (on the surroundings)
However, some of the heat supplied is also used to increase the internal energy of the system
Answer:
The answer to your question is given below.
Explanation:
The following data were obtained from the question:
Speed limit = 60 km/h
To know if the car was speeding, let us calculate the speed of the car.
This can be obtained as follow:
Distance (d) = 5 m
Convert 5 m to km
Recall:
1000 m = 1 km
5 m = 5/1000
5 m = 0.005 km
Time (t) = 0.2 sec.
Convert 0.2 sec to hour.
Recall:
3600 secs = 1 h
Therefore,
0.2 sec = 0.2/3600
0.2 sec = 5.56×10¯⁵ h
Thus,
Distance (d) = 0.005 km
Time (t) = 5.56×10¯⁵ h
Speed of car =?
Speed = Distance /time
Speed = 0.005/5.56×10¯⁵
Speed of the car = 90 km/h
Comparing the speed of the car (i.e 90 km/h) to the speed limit of the zone (i.e 60 km/h), we can see that the car is on a high speed since its speed (i.e 90 km/h) is higher than the speed limit of the zone (i.e 60 km/h).
Speed of the car = 90 km/h
Speed limit = 60 km/h
Difference = 90 – 60
Difference = 30 km/h
Therefore, the car is speeding by 30 km/h more compared to the speed limit.
Answer:
Li3PO4 - correct
FePO4 - correct
Cu3PO4 - correct
Mg3(PO4)2 - correct
Explanation:
In order to answer this question we must be conversant with the idea of valency as well as the idea of writing formula of ionic substances.
Lithium has a valency of 1 while PO4^3- has a valency of 3 so the correct formula of lithium phosphate must be Li3PO4 after the exchange of valencies.
Iron III has a valency of 3 while the phosphate ion also has a valency of 3 so the subscripts cancel out and iron III phosphate is FePO4.
Copper I ion has a valency of 1 and the phosphate ion has a valency of 3. When they exchange valencies, the formula of the compound is Cu3PO4.
Magnesium has a valency of 2 while the phosphate ion has a valency of 3. The exchange of valency gives us the formula Mg3(PO4)2.
