Hellpp Directions: Write True if the statement is correct, and false if it is incorrect.

1. The molecular formula can be calculated from the empirical formula if the molar

2. The molar mass represents the total mass, or 100 % of the compound.

mass is unknown.

3. Molecular formula gives the relative number of atoms of each element in the compound. 4. We can obtain the molecular formula from the empirical formula if we know the

molecular weight of the compound.

5. If a compound's chemical formula cannot be reduced any more, then the empirical formula is the same as

the molecular formula.​

The scheme below is from a series of reactions that are part of a synthesis of vitamin a. answer the following questions with reference to this scheme. (i) what is "reagent a"? (ii) draw a step-by-step mechanism which explains the formation of compound c from compound b (iii) which reagents would you use to form compound e from compounds c and d (reagents b and c)? for each reagent suggested above in (ii) explain the role of the reagent in the reaction to (iv) form compound e. you may wish to do this by drawing a mechanism. 1. addition of reagent a но reagent a 2. н,о" thо oh нон-с compound a. compound b. compound c .ch-оh 1. reagent b "сно 2. reagent c сh oh compound e. compound d.

What is true for a substance that releases energy

Which of the following nuclei would be the least stable a 2 protons, 2 neutrons b 1 proton 1 neutron c 1 proton 3 neutrons d 1 proton 2 neutrons