The initial mass of sodium hydroxide is 3.3 g (answer C)
<u><em>calculation</em></u>
Step 1 : find the moles of iron (ii) hydroxide ( Fe(OH)₂
moles = mass÷ molar mass
from periodic table the molar mass of Fe(OH)₂ = 56 + [16 +1]2 = 90 g/mol
moles is therefore = 3.70 g÷ 90 g/mol = 0.041 moles
Step 2: use the mole ratio to calculate the moles of sodium hydroxide (NaOH)
from given equation NaOH : Fe(OH)₂ is 2 :1
therefore the moles of NaOH = 0.041 x 2 = 0.082 moles
Step 3: find mass of NaOH
mass = moles x molar mass
from the periodic table the molar mass of NaOH = 23 +16 +1 = 40 g/mol
mass = 0.082 moles x 40 g/mol = 3.3 g ( answer C)
Is this supposed to be a question?????
Answer: Mutations can cause instant adaptations, while natural selection is the process by which adaptations occurs over a series of generations. Adaptations are changes or processes of changes by which an organism or species becomes better suited for its environment. A mutation is an alteration of the DNA sequence.
The number of Zn particles (atoms of Zn ) in the first sample, and Zn ions are going to be the same,
Also mass of Zn are going to be the same, because of electrons are too small, and would not have influence on mass.
