Question

please write the major product for these problems and explain why. thank you in advance !

U Delete Spam ... 7 Which reagent can cause the following transformation ? Page 3 нсон Hc OH A) KC0 B) NaBH: C) LAH. D) HNO; 8)Reaction of ethylmagnesium bromide with H2CO (formaldehyde) followed by treatment with A) a primary alcohol B) a secondary alcohol C) a tertiary alcohol D) an ether water gives 9) Nickel has 10 valence electrons. The formula for Nickel carbonyl is A) Ni (CO) B) Ni(CO), C) Ni(CO). D) Ni(CO); 10) What is the product of the following reaction PCCCHI,C12 HC- oh HC OH HCOCH, нс Part B 252 points)

Answer 1

7)

When carboxylic acids are treated reducing agents forms initially aldehydes or ketones finally forms alcohols.

Since potassium dichromate (option A) and Nitric acid (option D) are oxidizing agents. Hence these are not correct answers.

Lithium aluminium hydride (option C) can reduce Carboxylic acids to alcohols.

Even though NaBH_​​4 is a reducing agent, it is a weak reducing agent than NaBH_​​​4. Hence it cannot reduce Carboxylic acids to alcohols.

Option C is correct.

CH₃COOH LiLiAlH4----> CH₃CH₂OH

8) When Ethyl magnesium bromide is treated with formaldehyde followed by treatment with water gives primary alcohols. Here 1-propanol is formed.

When Ethyl magnesium bromide is treated with aldehydes other than formaldehyde followed by treatment with water gives secondary alcohols.

When Ethyl magnesium bromide is treated with Ketones followed by treatment with water gives tertiary alcohols.

CH₃CH₂MgBr + HCHO ---------> CH₃CH₂CH₂OMgBr

CH₃CH₂CH₂OMgBr + H₂O --------> CH₃CH₂CH₂OH

9)

Electronic configuration of Nickel (Z= 28) is

[Ar]4S²3d¹⁰

It has 10 electrons in its valency shell.

As Nickel atom and Nickel in its compound also have 10 electrons in its valency shell. Nickel is in zero oxidation state in its compound.

The compound is Ni(CO)₄ Nickel Tetra Carbonyl (0)

In this EAN ( Effective Atomic Number) of Nickel is 36. Hence it is more stable.

10)

PCC means Pyridinium chloro chromate

It is a mild oxidising agent which oxidises primary alcohols to aldehydes.

It strong oxidizing agents are used, final product is carboxylic acids but not the aldehydes.

CH₃CH₂OH + PCC/CH₂Cl_​​2 ----------> CH₃CHO

Ethanol (Ethanal)