Answer:
microorganism can bee seen yes
Answer:
Chemical changes
Explanation:
a)Burning a piece of charcoal - chemical change
b) Heating copper (ii) carbonate strongly - chemical change
c) Heating Zinc oxide strongly - chemical change
The given types of reaction indicates chemical changes. A chemical change is one in which a new kind of matter is formed. It is always accompanied by energy changes. The process is not easily reversible and hence, it is a permanent procedure.
Burning of charcoal produces a new kind of produces in the combustion process.
Both heating of copper(ii)carbonate strongly and zinc oxide will lead to a decomposition reaction in which new compounds are formed.
Answer:
10.77%
Explanation:
Molar mass of Cu = mass deposited/number of moles of Cu
Molar mass of Cu = 0.4391 g/6.238x10^-3 moles
Molar mass of Cu = 70.391 g/mol
%error = 70.391 g/mol - 63.546 g/mol/63.546 g/mol × 100
%error = 10.77%
Answer : Option B) 360 g/mol
Explanation : The antibacterial agent Penicillin N contains 8.92% of sulfur by mass. So we have to calculate the molar mass of penicillin N will be as
i) 256 X 0.0892 = 22.83 g/mol this cannot be the answer as it doesn't shows any sign of sulfur being present even in 1 mole.
ii) 360 X 0.0892 = 32.112 g/mol This is the closest to the molar mass of sulfur which is 32.06 g/mol; this means it contains 1 mole of sulfur.
iii) 390 X 0.0892 = 34.78 g/mol this also fails to prove the answer as correct.
iv) 743 X 0.0892 = 66.27 g/mol This is not even falling in the range of sulfur mole.
Hence we can confirm that the answer is Option B
<span>Balanced half-reaction: Au</span>⁺<span>(aq) </span>→ <span> Au</span>³⁺(aq) + 2e⁻.
Oxidation reaction is increasing of oxidation number of element, because element or ion lost electrons in chemical reaction.
Gold lost two electrons and change oxidation number from +1 to +3.
Reduction is lowering oxidation number because element gain electrons.
