Question 5 is the second one.
Answer:
Equation of reaction:
a) 2HCl + Ba(OH)2 ==> CaCl2 + 2H2O
b) Molarity of base = 0.042 M.
Explanation:
Using titration equation
CAVA/CBVB = NA/NB
Where NA is the number of mole of acid = 2
NB is the number of mole of base = 1
CA is the molarity of acid =0.15M
CB is the molarity of base = to be calculated
VA is the volume of acid = 25 ml
VB is the volume of base = 44.45mL
Substituting
0.15×25/CB×44.45 = 2/1
Therefore CB =0.15×25×1/44.45×2
CB = 0.042 M.
Answer:
The second one
Explanation:
Gas pressure is caused by gas molecules bouncing off the container walls and each other. Every time a molecule changes direction because it hits a wall, the change in momentum results in a small push. Due to the large number of molecules involved, the pushes add up to a large amount of pressure.
Answer:7 atom of carbon+5atom of hydrogen +3atom of nitrogen +6 atom of oxygen =21
The first blank can be filled with the Heliocentric model, and the second blank can be filled with Copernicus.
The heliocentric model known as heliocentrism was proposed by the Renaissance astronomer, mathematician, and the Catholic cleric Nicolaus Copernicus resulting in the Copernican revolution.
It is the astronomical model, in which the planets and the Earth revolve around the Sun positioned at the middle of the Solar system. Factually, the heliocentric model was in contrast to geocentrism, in which Earth is positioned at the center of the Solar system.
