Question

1. choose the best answer. what is this reaction classified as? $2na_3po_4 + 3cacl_2 \

ightarrow 6nacl + ca_3(po_4)_2$ combustion single replacement oxidation - reduction double replacement

Explanation:

1. For question 11: Bubbles are visual evidence that a gaseous product has formed, as gases disperse from a reaction mixture in this way.
2. For question 12: The reaction $2Na_3PO_4 + 3CaCl_2

ightarrow 6NaCl + Ca_3(PO_4)_2$ involves two ionic compounds swapping their positive and negative ions to form new compounds, which is a double replacement reaction.

Answer:

1. gas
2. double replacement