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.
Answer
:
2. Hydrogen forms bonds through the overlap of 1s atomic orbitals and the sharing of electrons between atoms. Carbon forms bonds through the overlapping of sp hybrid atomic orbitals and the sharing of electrons between carbon atoms.
Explanation:
The H-H bond is formed by the overlap of two 1s orbitals and the sharing of electrons between the two atoms.
A carbon atom must use the overlap of hybridized atomic orbitals and the sharing of electrons to bond with another carbon atoms.
1. is <em>wrong</em> because H can use only its <em>1s orbital</em> for bonding.
3. is <em>wrong</em> because C must <em>share electrons</em> to form a carbon-carbon bond.
4. is <em>wrong</em> because <em>C does NOT use overlapping of 2s orbitals</em> for bonding. It uses the overlap of hybridized orbitals.
5. is <em>wrong</em> because H must <em>share electrons</em> to form an H-H bond.
Protons and neutrons
electrons just revolve around it
Answer:
<span>ρ≅13.0⋅g⋅m<span>L<span>−1</span></span></span> = <span>13.0⋅g⋅c<span>m<span>−3</span></span></span>
Explanation:
<span>Density=<span>MassPer unit Volume</span></span> = <span><span>75.0⋅g</span><span><span>(36.5−31.4)</span>⋅mL</span></span> <span>=??g⋅m<span>L<span>−1</span></span></span>
Note that <span>1⋅mL</span> = <span>1⋅c<span>m<span>−3</span></span></span>; these are equivalent units of volume;
i.e. <span>1⋅c<span>m3</span></span> = <span>1×<span><span>(<span>10<span>−2</span></span>⋅m)</span>3</span>=1×<span>10<span>−6</span></span>⋅<span>m3</span>=<span>10<span>−3</span></span>⋅L=1⋅mL</span>.
