a) The reaction is exothermic since the overall enthalpy change is negative. this means that the system has lost energy to the environment, namely, the apparatus and due to drought.
b) We first calculate the number of moles in 3.55 grams of magnesium.
number of moles= mass/ atomic mass
=3.55/24
=0.1479 moles(to 4sf)
now, if 2 moles of magnesium give -1204kJ
How much energy is given by 0.1479 moles
= (0.1479×-1204kJ)
=-89.0358kJ (don't forget the negative sign)
c) two molesof MgO produces -1204kJ of energy
then -234kJ will be produced by
=(-234kJ×2moles)/1204kJ
=0.3887moles
one mole of MgO weighs 24+16=40
therefore the mass produced is 0.3887moles×40=15.548grams
(d) we first find the number of moles of MgO in 40.3 grams
number of moles=mass/RFM
=40.3g/40= 1.0075moles
if 2 moles of MgO give 1204 kJ then decomposing 1.0075 moles requires
(1.0075 moles×1204kJ)/2=606.515kJ
You have to be romantic with her and give her presents and always say that she is right.
Answer: 25.8 g of 
will be produced from the decomposition of 73.4 g of 
Explanation:
To calculate the moles :
The balanced chemical reaction is:
According to stoichiometry :
2 moles of produce = 3 moles of
Thus 0.242 moles of will produce= 
of
Mass of = 
Thus 25.8 g of will be produced from the decomposition of 73.4 g of
Answer:
1. chloroplast
2. they prevent some proteins to function how they normally function
Explanation:
Answer:
a) 
b) 
c) 
Carbon: 
Explanation:
<u>Nitrate</u>
First of all, is important to know that:
a) 10 ppm of nitrate (
) is equal to
b) The molecular weight of nitrate is 
c) Nitrate has 14 mg of N per 62 mg of NO3
<u>Carbon</u>
Carbonate has 12 mg of C per 60 mg of 
Bicarbonate has 12 mg of C per 61 mg of 
