Answer:
Three primary reasons. First, there is simply more water-covered places than dry ground places for the animals and plants to have lived. Second, the seas are much more crowded with the kinds of life that leave fossils than the land is. Third, the process that form fossils work very well under water.
Explanation:
Equation of reaction
Hcl+NaoH-->Nacl+H2O
1:1
Using the formula CaVa/CbVb=na/nb
Ca(Concentation of acid)= 0.100M
Cb(Concentration of base)=0.200M
Va=?
VB=50.00ml
na=1
nb=1
from the formula
Va= CbVbna/Canb
Va= 0.2*50*1/0.1*1
=10/0.1=100ml
Therefore volume of acid = 100ml
Answer:
ΔH = 2.68kJ/mol
Explanation:
The ΔH of dissolution of a reaction is defined as the heat produced per mole of reaction. We have 3.15 moles of the solid, to find the heat produced we need to use the equation:
q = m*S*ΔT
<em>Where q is heat of reaction in J,</em>
<em>m is the mass of the solution in g,</em>
<em>S is specific heat of the solution = 4.184J/g°C</em>
<em>ΔT is change in temperature = 11.21°C</em>
The mass of the solution is obtained from the volume and the density as follows:
150.0mL * (1.20g/mL) = 180.0g
Replacing:
q = 180.0g*4.184J/g°C*11.21°C
q = 8442J
q = 8.44kJ when 3.15 moles of the solid react.
The ΔH of the reaction is:
8.44kJ/3.15 mol
= 2.68kJ/mol
The polarity of a water molecule
comes from the uneven distribution of electron density of hydrogen and oxygen
atom. The oxygen in the water molecule is more electronegative than the
hydrogen. Water has a partial positive charge near the hydrogen atom and a
partial negative charge near the oxygen atom. The result of this
electrostatic attraction results in the bond called hydrogen bond. Also,
because of this bond, it has the ability to dissolve most of the solutes due to
its polarity and bonding.
