<span>You must multiply the bond enthalpy by each broken or formed bond.
The C - H bond = 414k Joules/ mol, but that is only applicable per bond.
The C3H8 molecule has 8*C-H bonds that have to break. You have to account all the bonds that break and form to get the DH for the reaction.
Because of the Lewis structure of Propane C3h8 you only use 8 in </span><span>c3h8 has 3-C and 8-C.</span>
5.50M NaOH must be added to 680.0 mL of a buffer, The amount of NaOH is mathematically given as
V=2.107mL
<h3>What is the volume of 5.50M NaOH?</h3>
Generally, the equation for Chemical Reaction is mathematically given as
CH3COOH+OH^{-} ⇄ CHCOO^{-} + H2O
Therefore
pka=-log(1.8*10{-5})
pKa=5-0.25527
pKa=4.3447
Hence

x=0.0115898
Volume of NaOH
V=0.0021072L
V=2.107mL
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The formula of chalcopyrite is CuFeS₂.
The molar mass of chalcopyrite - 183.5 g/mol
The mass of Cu in 1 mol of chalcopyrite is - 63.5 g
When 183.5 g of chalcopyrite is mined, the mass of Cu obtained - 63.5 g
So if 63.g of Cu is needed mass of chalcopyrite required - 183.5 g
Then to gain 370 g of pure Cu - mass of chalcopyrite needed -183.5/63.5 x 370
therefore mass of chalcopyrite to be mined - 1069.21 g
Answer:
Density, mass of a unit volume of a material substance. The formula for density is d = M/V, where d is density, M is mass, and V is volume. Density is commonly expressed in units of grams per cubic centimetre. ... For example, the density of air is 1.2 kilograms per cubic metre.
The correct answer is oil