<span>Mg + O2 > MgO. In reactant side, 2 O atoms and 1 Mg are present. In product side, 1 Mg and O atoms are present. Put 2 in product side to balance O atoms and 2 at Mg in reactant side to balance Mg atoms. Therefore the balanced equation becomes, 2Mg + O2 ----> 2MgO. Hope it helps.</span>
Molarity is expressed as:
Molarity = moles / liter
Given that the cell is rod-shaped, its volume is calculated using the formula for a cylinder's volume:
V = πr²L
V = π * (0.6)² * 4.9
V = 5.54 μm³
1 Liter = 10³ mm³
1 mm = 10³ μm
1 mm³ = 10⁹ μm³
1 liter = 10¹² μm³
So the volume in liters is:
5.54 x 10⁻¹² L
Moles = molarity * liters
Moles = 0.0029 * 5.54 x 10⁻¹²
Moles = 1.61 x 10⁻¹⁴
To get the number of molecules, we multiply the moles by Avagadro's number
Number of molecules = 1.61 x 10⁻¹⁴ * 6.02 x 10²³
There are 9.69 x 10⁹ molecules in the cell
Answer:- Third choice is correct, 17.6 moles
Solution:- The given balanced equation is:
Al_2(SO_4)_3+6KOH\rightarrow 2Al(OH)_3+3K_2SO_4
We are asked to calculate the moles of potassium hydroxide needed to completely react with 2.94 moles of aluminium sulfate.
From the balanced equation, there is 1:6 mol ratio between aluminium sulfate and potassium hydroxide.
It is a simple mole to mole conversion problem. We solve it using dimensional set up as:
2.94molAl_2(SO_4)_3(\frac{6molKOH}{1molAl_2(SO_4)_3})
= 17.6 mol KOH
So, Third choice is correct, 17.6 moles of potassium hydroxide are required to react with 2.94 moles of aluminium sulfate.
