<u>Answer:</u> The true statement is iron can reduce
to gold metal
<u>Explanation:</u>
Single displacement reaction is defined as the reaction in which more reactive element displaces a less reactive element from its chemical reaction.
The reactivity of metal is determined by a series known as reactivity series. The metals lying above in the series are more reactive than the metals which lie below in the series.

Metal A is more reactive than metal B.
We are given:
Iron can reduce copper, silver can reduce gold, sodium can reduce iron and copper can reduce silver metal.
The increasing order of reactivity thus follows:

where, sodium is most reactive and gold is least reactive
For the given options:
<u>Option 1:</u> Copper cannot easily reduce sodium ion to sodium metal because it is less reactive.

<u>Option 2:</u> Iron cant easily reduce gold ion to gold metal because it is more reactive.

<u>Option 3:</u> Silver cannot easily reduce iron ion to iron metal because it is less reactive.

Hence, the true statement is iron can reduce
to gold metal
The way you calculate the empirical formula is to firstly assume 100g. To find each elements moles you take each elements percentage listed, times it by one mole and divide it by its atomic mass. (ex: moles of K =55.3g x 1 mole/39.1g, therefore there is 1.41432225 moles of Potassium) Once you’ve completed this for every element you list each elements symbol beside it’s number of moles and divide by the smallest number because it can only go into its self once. After you’ve done this, you’ve found your empirical formula, which is the simplest whole number ratio of atoms in a compound. I’ve added an example of a empirical question I completed last semester :)
Answer:
83°C
Explanation:
The following were obtained from the question:
M = 40g
C = 4.2J/g°C
T1 = 91°C
T2 =?
Q = 1300J
Q = MCΔT
ΔT = Q/CM
ΔT = 1300/(4.2x40)
ΔT = 8°C
But ΔT = T1 — T2 (since the reaction involves cooling)
ΔT = T1 — T2
8 = 91 — T2
Collect like terms
8 — 91 = —T2
— 83 = —T2
Multiply through by —1
T2 = 83°C
The final temperature is 83°C
Answer:
Ionic equation:
Na⁺(aq) + OH⁻(aq) + H⁺(aq) + Cl⁻(aq) → H₂O(l) + Na⁺(aq) + Cl⁻ (aq)
Explanation:
Chemical equation:
NaOH(aq) + HCl(aq) → H₂O(l) + NaCl (aq)
Balanced chemical equation:
NaOH(aq) + HCl(aq) → H₂O(l) + NaCl (aq)
Ionic equation:
Na⁺(aq) + OH⁻(aq) + H⁺(aq) + Cl⁻(aq) → H₂O(l) + Na⁺(aq) + Cl⁻ (aq)
Net ionic equation:
OH⁻(aq) + H⁺(aq) → H₂O(l)
The Cl⁻(aq) and Na⁺ (aq) are spectator ions that's why these are not written in net ionic equation. The water can not be splitted into ions because it is present in liquid form.
Spectator ions:
These ions are same in both side of chemical reaction. These ions are cancel out. Their presence can not effect the equilibrium of reaction that's why these ions are omitted in net ionic equation.