Complete each statement with the correct term/compound:

1. The carbonyl carbon in an aldehyde is __________ hybridized. (sp2)

2. The nucleophilic addition of HCN to acetaldehyde gives __________ (the product). (Lactonitrile / acetaldehyde cyanohydrin, CH3CH(OH)CN)

3. The test that distinguishes aldehydes from ketones using ammoniacal silver nitrate is called __________ test. (Tollens')

4. The aldol condensation of acetaldehyde (CH3CHO) with dilute NaOH gives __________ as the initial product. (3-Hydroxybutanal)

5. Benzaldehyde does not undergo aldol condensation because it lacks __________. (alpha-hydrogen)

6. Clemmensen reduction uses __________ as the reagent, under __________ conditions. (Zn-Hg / conc. HCl; acidic)

7. The Wolff-Kishner reduction converts C=O to __________ using __________ in KOH. (CH2; hydrazine / NH2NH2)

8. The product of the iodoform reaction is __________, which is __________ in color. (CHI3 / iodoform; yellow)

9. 2,4-DNP test is positive for __________ (type of compounds). (Both aldehydes and ketones)

10. Diethyl ketone gives a __________ iodoform test because it has no __________ group. (negative; CH3CO-)

11. In the Cannizzaro reaction of HCHO: 2HCHO + NaOH → __________ + __________. (HCOONa / sodium formate; CH3OH / methanol)

12. LiAlH4 reduces C=O to __________ (oxygen __________). (C-OH; retained as alcohol)

13. The intermediate in nucleophilic addition to C=O that is sp3-hybridized is called the __________ intermediate. (tetrahedral alkoxide)

14. Ethanol gives a positive iodoform test because it is first oxidized to __________ by I2/NaOH. $\frac{acetaldehyde}{CH3CHO}$

15. The reaction of phenylhydrazine with a ketone gives a __________, which contains the __________ group. (phenylhydrazone; C=NNHC6H5)