Vitamin , cyanocobalamin, is essential for human nutrition. it is concentrated in animal tissue but not in higher plants. although nutritional requirements for the vitamin are quite low, people who abstain completely from animal products may develop a deficiency anemia. cyanocobalamin is the form used in vitamin supplements. it contains 4.34% cobalt by mass. calculate the molar mass of cyanocobalamin, assuming that there is one atom of cobalt in every molecule of cyanocobalamin.

1360.0 g/mol

Explanation:

If there is one atom of cobalt in every molecule of cyanocobalamin its chemical formula must be

CoX₂, so there is 1 mol of cobalt for 1 mol of the compound. The molar mass of the cobalt is 59 g/mol. So, there is 59 g of cobalt in 1 mol of the cyanocobalamin and it represents 4.34% of the total mass, so:

0.0434m = 59

m = 1359.45 g of cyanocobalamin

The molar mass of the molecule is the mass divided by the number of moles (which is 1), so it is:

M = 1359.45 g/mol = 1360.0 g/mol

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e

2b2t

explanation:

2b2t