You are confronted with an unknown metal, M, and need to determine its identity. Using the following information identify the metal.
M(s) Reacts vigorously with water and acid.
M(s) does not react with K+(aq)
M(s) reacts with Co+2(aq)
M(s) does not react with Ca+2(s)
M(s) reacts with Na+(aq)
To identify the unknown metal M, we can analyze its reactions with different substances.
First, we know that M reacts vigorously with water and acid. This suggests that M is a metal higher in the reactivity series, as metals lower in the reactivity series tend to be less reactive and do not readily react with water or acid.
Next, we can consider the reactions of M with various ions:
- M(s) does not react with K+(aq): This indicates that M is unable to displace potassium from its compounds, suggesting that M is less reactive than potassium.
- M(s) reacts with Co+2(aq): Since M reacts with cobalt ions, it indicates that M is more reactive than cobalt.
- M(s) does not react with Ca+2(aq): This implies that M is unable to displace calcium from its compounds, indicating that M is less reactive than calcium.
- M(s) reacts with Na+(aq): The reaction of M with sodium ions indicates that M is more reactive than sodium.
Based on these observations, we can conclude that the unknown metal M is more reactive than cobalt and sodium but less reactive than potassium and calcium.
Therefore, based on its reactivity with different substances, the metal M can be identified as magnesium (Mg).