Answer:
C. a change in the total mass of the product
Explanation:
A chemical reaction is a reaction that alters the chemical composition of the substances involved. Based on the options in this question, a chemical reaction possess the following features:
- The atoms of the substance called reactants are rearranged into products but the total number of atoms remain the same after the reaction.
- A change in odor occurs as one of the indicators that a chemical reaction has taken place.
- Energy is either absorbed (endothermic) or released (exothermic) in the chemical reaction.
However, one untrue option is that "there is a change in the total mass of the product". The total mass of a chemical reaction does not change i.e. remains the same, before or after the reaction in accordance to the law of conservation of mass.
Answer The ethanol is stabilized by strong intermolecular forces between the molecules.wer:
Explanation:
During the phase change represented by the heat of fusion the temperature does not change. The molecules in the liquid state has a higher degree of freedom but are stabilized by the strong hydrogen bonding requiring a larger into of energy to separate the molecules than the heat of fusion.
Answer:
120°
Explanation:
Valence electrons of boron = 2
Valence electrons of chlorine = 7
The total number of the valence electrons = 3 + 3(7) = 24
The Lewis structure is drawn in such a way that the octet of each atom in the molecule is complete. So,
The Lewis structure is:
There is no lone pair involved, so, It is of type AB₃.
According to the theory, the atoms will form a geometry in such a way that there is minimum repulsion and maximum stability.
So, it is of triangular shape, with bond angle , 120 ° .
Answer:
1) thiamine pyrophosphate -activation of aldehydes
2) coenzyme A -acyl group transfer
3) biotin -CO2 activation/transfer
4) NAD -oxidation/reduction
Explanation:
1. Thiamine pyrophosphate: This is a derivative of Vitamin B1 also known as thiamine. It contains a pyrimidine group linked to the thiazole ring. This connection is further linked to the pyrophosphate group. It functions as a coenzyme in all reactions involving alpha-keto acids. This produces activated aldehydes that could be subject to oxidation.
2. Coenzyme A: This cofactor is a thiol that reacts with carboxylic acids to form thioesters. In so doing, it carries the acyl group. In this condition, it can also be referred to as acyl CoA.
3. Biotin: Also known as Vitamin B7, biotin consists of an ureido ring merged with tetrahydrothiophene. The ureido ring contains the CO2 that can be transferred or activated. Five carboxylase enzymes use biotin as a cofactor in processes such as fat synthesis, glucose generation and the breakdown of sugar.
4. NAD: Nicotinamide adenine dinucleotide consists of two dinucleotides connected to each other at their phosphate groups. NAD exists in two states which are the NAD+ and NADH states. These two states serve as oxidizing and reducing agents respectively. The oxidizing agent becomes reduced to NADH after accepting electrons from other compounds. NADH donates an electron and becomes oxidized to NAD+.
The concentration as % by mass is calculated as below
mass of solute/mass of solvent x100
mass of solute(sugar) = 4g
mass of solvent(water) =46 g
= 4g/ 46 g x100 = 8.7%
