Answer chocies .......................
The correct option is B.
Stars live out most of their lives at MAIN SEQUENCE. Stars generally are divided into three major stages, these are:
1. Pro stars and pre-main sequence star
2. Main sequence and giant star
3. Variable stars
Major stages in the life of a star can last for millions of years.
Answer:
HCl for acid, NaOH for base.
Explanation:
Acids start with H.
Bases end with OH.
Answer:
Molality = 0.43 m
Explanation:
Given data:
Mass of barium sulfide = 25.4 g
Mass of water = 349 g (349 g/1000 = 0.349 Kg)
Molality of water = ?
Solution:
Number of moles of barium sulfide:
Number of moles = mass/molar mass
Number of moles = 25.4 g/169.39 g/mol
Number of moles = 0.15 mol
Molality:
Molality = number of moles o f solute/ Kg of solvent
Molality = 0.15 mol / 0.349 Kg
Molality = 0.43 m
