Answer:- 13.6 L
Solution:- Volume of hydrogen gas at 58.7 Kpa is given as 23.5 L. It asks to calculate the volume of hydrogen gas at STP that is standard temperature and pressure. Since the problem does not talk about the original temperature so we would assume the constant temperature. So, it is Boyle's law.
Standard pressure is 1 atm that is 101.325 Kpa.
Boyle's law equation is:

From given information:-
= 58.7 Kpa
= 23.5 L
= 101.325 Kpa
= ?
Let's plug in the values and solve it for final volume.

On rearranging the equation for 

= 13.6 L
So, the volume of hydrogen gas at STP for the given information is 13.6 L.
One of the ways to minimize a collision is to slow down: When you can't find an escape and you're definitely going to collide with something, you should slow your vehicle down as much as possible.
Hope this helps ^^
To find the chemical formula of an ionic compound, the first step is to find the charge of the 2 ions. As given already, the charge of sodium ion is 1+, and carbonate ion has a charge of 2-. We can picture it like that: Sodium ion loses 1 electron and carbonate ion gains 2.
The next step is to find how the 2 ions can lose and gain electrons equally. In this case, since each Na ion only loses 1 electron, it cannot satisfy the need of one carbonate ion, since they need 2, not 1. Therefore, 2 Na ions can cover the need of one carbonate ion. So, the ratio of Na to CO3 ion should be 2:1.
Now just combine the 2 ions, positive one at the front, which makes it NaCO3, make sure you do not add the charge and notice that CO3 is a molecule itself so do not remove the 3. Now because the ratio is 2:1, so the final formula is Na2CO3, no need to add 1 if the ratio is 1.
Your answer should be Na2CO3.
Answer:
i) During washing
ii) During Measurement
Explanation:
The two possible steps are :
<u>i) During washing </u>: during the washing method the residue may be not completely dried out and this residue ( water) will add up to the final product ( copper yield ) and this kind of error is called human error.
<u>ii) During measurement </u>: If the weighing instrument is faulty there might be addition in value of the final copper yield which will see the final yield value > 100% . this error occurs when the initial value and final value is been weighed