Which equation shows a reaction that will occur at room temperature and pressure?
A Br2(aq) + 2NaCl (aq) → 2NaBr(aq) + Cl 2(aq)
B Br2(aq) + 2NaI(aq) → 2NaBr(aq) + I2(aq)
C I2(aq) + 2NaCl (aq) → 2NaI(aq) + Cl 2(aq)
D I2(aq) + 2NaBr(aq) → 2NaI(aq) + Br2(aq)
F2 replaces other halogen ions below it.
Cl2 replaces halogen ions below it.
Br2 replaces halogen ions below it.
I2 replaces halogen ions below it.
So you know A isn't right. Which one is?
To determine which reaction will occur at room temperature and pressure, we need to consider the reactivity of the elements involved.
Bromine (Br2) is a highly reactive element, and so is chlorine (Cl2). Sodium (Na), on the other hand, is a relatively less reactive metal. Iodine (I2) is less reactive than bromine and chlorine.
When we compare the reactivity of the halogens (Group 17 elements), we find that the reactivity decreases as we move down the group from top to bottom. This means that iodine is less reactive than bromine and chlorine.
In a displacement reaction, a more reactive halogen can displace a less reactive halogen from its compound. So, in the reaction, the more reactive halogen will be replaced by the less reactive halogen.
Looking at the given options,
A) Br2(aq) + 2NaCl(aq) → 2NaBr(aq) + Cl2(aq)
B) Br2(aq) + 2NaI(aq) → 2NaBr(aq) + I2(aq)
C) I2(aq) + 2NaCl(aq) → 2NaI(aq) + Cl2(aq)
D) I2(aq) + 2NaBr(aq) → 2NaI(aq) + Br2(aq)
In option B, bromine (Br2) is being replaced by iodine (I2). Since iodine is less reactive than bromine, this reaction is more likely to occur at room temperature and pressure.
Therefore, the correct equation showing a reaction that will occur at room temperature and pressure is B) Br2(aq) + 2NaI(aq) → 2NaBr(aq) + I2(aq).