Answer:
a) T
b) T
c) F
d) F
e) T
f) T
g) T
h) F
I) F
j) F
k) F
l) F
Explanation:
The w/v concentration is obtained from, mass/volume. Hence;
%w/v= 50/1000= 5%
In the %w/w we have;
25g/100 g = 25% w/w
In combustion reaction, energy is given out hence it is exothermic.
Neutralization reaction yields a salt and water
% by mass of carbon is obtained from;
8× 12/114 × 100 = 84.1%
All the ionic substances mentioned have very low solubility in water.
One mole of a substance contains the Avogadro's number of each atom in the compound.
There are two iron atoms so one mole contains 2× 55.85 g of iron.
Some sulphates such as BaSO4 are insoluble in water.
Halides are soluble in water hence NaI is soluble in water.
The equation does not balance with the given coefficients because the number of atoms of each element on both sides differ.
The equation represents a decomposition of calcium carbonate as written.
Cu + 2H2SO4 ⟶ CuSO4 + SO2 + 2H20
In left hand side of the equation.
Cu = 1 atom
H = 4 atoms
S = 2 atoms
O = 8 atoms
In right hand side of the equation.
Cu = 1 atom
S = 2 atoms
0 = 8 atoms
H = 4 atoms
• All the atoms are balanced in the left and right side of the equation and it satisfies the law of conservation of mass.
• Equation is balanced and correct.
*See the attachment .
PH is the water and it color blue
Answer: Option (4) is the correct answer.
Explanation:
It is known that density is mass divided by volume.
Mathematically, Density = 
Since, density is directly proportional to mass. So, more is the mass of an element more will be its density.
Mass of magnesium is 24.305 g/mol.
Mass of barium is 137.327 g/mol.
Mass of beryllium is 9.012 g/mol
Mass of radium is 226 g/mol.
Hence, radium has more mass therefore it will have the greatest density at STP.
Answer:
Ozone layer depletion causes increased UV radiation levels at the Earth's surface, which is damaging to human health. Negative effects include increases in certain types of skin cancers, eye cataracts and immune deficiency disorders.
