Hey there!
Chemical changes are changes in object's chemical compounds and chemical compositions, and often can't be reversed.
Here's an example:
If you have a piece of paper and you happen to burn it, that can't be reversed.
In other words, it can't be "un-burned". Nothing can restore it to its previous state.
Hopefully this helped!
Answer:
54
Explanation:
Given symbol of the element:
I⁻
Number of electrons found in an ion with the symbol:
This is a iodine ion:
For an atom of iodine:
Electrons = 53
Protons = 53
Neutrons = 74
An ion of iodine is one that has lost or gained electrons.
For this one, we have a negatively charged ion which implies that the number of electrons is 1 more than that of the protons.
So, number of electrons = 53 + 1 = 54
The number of electrons in this ion is 54
Answer:
The final temperature is 39.58 degree Celsius
Explanation:
As we know
Q = m * c * change in temperature
Specific heat of water (c) = 4.2 joules per gram per Celsius degree
Substituting the given values we get -
5750 = 335 * 4.2 * (X - 35.5)
X = 39.58 degree Celsius
Answer:
The theoretical yield of urea = <u>120.35kg</u>
The percent yield for the reaction = <u>72.70%</u>
Explanation:
Lets calculate -
The given reaction is -
→
Molar mass of urea 
= 60g/mole
Moles of 
= 
(since 
)
= 4011.76 moles
Moles of 
= 
= 
= 2386.36 moles
Theoritically , moles of required = double the moles of
but , 
, the limiting reagent is
Theoritical moles of urea obtained = 
= 
Mass of 2005.88 mole of =
= 120352.8g
= 120.35kg
Therefore , theroritical yeild of urea = 120.35kg
Now , Percent yeild = 
72.70%
Thus , the percent yeild for the reaction is 72.70%
