Question

question 4 (1 point)
balance the reaction, do not leave any fractions, dont leave anything blank, then answer the questions about the reaction
1 ca(cn)₂ + 2 k₃po₄ → 3 kcn + 4 ca₃(po₄)₂(s)
this is an 5 reaction. is this a redox reaction? (yes/no)6, because neither cn⁻¹, ca⁺², k⁺¹, nor po₄⁻³ change oxidation state.
will the reaction happen as it is written? (yes/no)7, because a product is a solid and leaves the area of the reaction. the reverse reaction would not happen.
a. 1 b. 2 c. 3 d. 4 e. 5 f. 6 g. 7 h. 8
i. 9 j. 10 k. 12 l. 14 m. 16 n. 18 o. 20 p. 21
q. 24 r. 26 s. 28 t. synthesis u. decomposition
v. single displacement w. double displacement x. neutralization
y. combustion z. yes aa. no bb. reactive cc. stable
dd. oxidized ee. reduced

Explanation:

Step1: Balance Ca atoms

On the right - hand side, there are 3 Ca atoms in \(Ca_3(PO_4)_2\). So, we put a coefficient of 3 in front of \(Ca(CN)_2\).
\(3Ca(CN)_2+K_3PO_4
ightarrow KCN + Ca_3(PO_4)_2\)

Step2: Balance \(PO_4\) groups

On the right - hand side, there are 2 \(PO_4\) groups in \(Ca_3(PO_4)_2\). So, we put a coefficient of 2 in front of \(K_3PO_4\).
\(3Ca(CN)_2 + 2K_3PO_4
ightarrow KCN+Ca_3(PO_4)_2\)

Step3: Balance K atoms

On the left - hand side, there are \(2\times3 = 6\) K atoms in \(2K_3PO_4\). So, we put a coefficient of 6 in front of \(KCN\).
\(3Ca(CN)_2+2K_3PO_4
ightarrow6KCN + Ca_3(PO_4)_2\)

Step4: Identify the reaction type

In a double - displacement reaction, the general form is \(AB+CD
ightarrow AD + CB\). Here, \(Ca(CN)_2\) (\(AB\) where \(A = Ca^{2 +}\) and \(B=CN^{-}\)) and \(K_3PO_4\) (\(CD\) where \(C = K^{+}\) and \(D = PO_4^{3-}\)) react to form \(KCN\) (\(AD\)) and \(Ca_3(PO_4)_2\) (\(CB\)). So, it is a double - displacement reaction.

Step5: Determine if it is a redox reaction

In a redox reaction, there is a change in oxidation states of atoms. For \(CN^{-}\): C has an oxidation state of \(+2\) and N has an oxidation state of \(-3\) (sum \(+2-3=-1\)). For \(Ca^{2+}\), oxidation state is \(+2\). For \(K^{+}\), oxidation state is \(+1\). For \(PO_4^{3 -}\): P has an oxidation state of \(+5\) (\(x+4\times(- 2)=-3\) gives \(x = + 5\)) and O has an oxidation state of \(-2\). Since no oxidation states change, it is not a redox reaction.

Step6: Determine if the reaction occurs

According to the solubility rules, \(Ca_3(PO_4)_2\) is insoluble (forms a solid). In a double - displacement reaction, if a precipitate (solid), a gas or a weak electrolyte is formed, the reaction occurs. Since \(Ca_3(PO_4)_2\) is a solid (precipitate), the reaction occurs as written.

Answer:

1. \(3\) (C)
2. \(2\) (B)
3. \(6\) (no option provided in the given letters, but if we assume the closest is not there. However, based on balancing)
4. \(1\) (A)
5. W (double displacement)
6. AA (no)
7. Z (yes)