Answer:
0.1056 mole
Explanation:
As Sally knows that the charge on the metal ion is n = +2

In that compartment ![$[M^{n+}]=[m^{2+}]=8.279 \ M$](https://tex.z-dn.net/?f=%24%5BM%5E%7Bn%2B%7D%5D%3D%5Bm%5E%7B2%2B%7D%5D%3D8.279%20%5C%20M%24)
The volume of the
taken in that compartment = 6.380 mL
So, the number of moles of 
= 52.82 m mol
= 0.05280 mol

But n = 2
Therefore, moles of
= 2 x moles of 
= 2 x 0.05282
= 0.1056 mole
B because it can stabilize
Answer:
Option D. 230 J
Explanation:
We'll begin by calculating the temperature change of the iron. This can be obtained as follow:
Initial temperature (T₁) = 50 °C
Final temperature (T₂) = 75 °C
Change in temperature (ΔT) =?
ΔT = T₂ – T₁
ΔT = 75 – 50
ΔT = 25 °C
Thus, the temperature change of the iron is 25 °C.
Finally, we shall determine the amount of heat energy used. This can be obtained as follow:
Mass (M) = 20 g
Change in temperature (ΔT) = 25 °C
Specific heat capacity (C) = 0.46 J/gºC
Heat (Q) =?
Q = MCΔT
Q = 20 × 0.46 × 25
Q = 230 J
Thus, the amount of heat used was 230 J
Answer:
Y, Q, W, Z and X
Y > Q > W > Z > X
Explanation:
To know the most reactive element, the element will be able to displace other metal in it compound. We also have to observe if the reaction occur. If the reaction didn't occur, that means the element is not reactive than the metal found in the other reactant. Invariably their will be no displacement.
Q + w+ Reaction occurs
Q element displace the metal w in it compound . This means Q is more reactive.
x +z+ No reaction
No reaction here. This means x is less reactive than z as it couldn't displace z in it compound.
w + z+ Reaction occurs
w is more reactive than z as it displaces z in it compound.
Q+ + Y Reaction occurs
Y is more reactive than Q as it displaces Q in it compounds.
Therefore, the most reactive to the least reactive is arrange as follows.
Y, Q, W, Z and X