Answer: 72 grams of 
are needed to completely burn 19.7 g 
Explanation:
According to avogadro's law, 1 mole of every substance weighs equal to molecular mass and contains avogadro's number 
of particles.
To calculate the number of moles, we use the equation:
Putting in the values we get:
According to stoichiometry:
1 mole of 
requires 5 moles of oxygen
0.45 moles of require= 
moles of oxygen
Mass of 
72 grams of are needed to completely burn 19.7 g
Answer:
At the end of cell cycle (mitosis replication), two daughter cells are produced. Each contains exactly the same number of DNA content.
Answer:
Explanation:
1. Volume of sealed tube
Assume the sealed tube is a right circular cylinder in which the cap and the base are also 4.20 mm thick.
Its outside dimensions are 155 mm long × 10.0 mm diameter.
Its inside dimensions are
h = 155 mm - 2 × 4.20 mm = 146.6 mm
r = 5.0 mm - 4.20 mm = 0.8 mm
V = πr²h = π(0.8)²× 146.6 mm³ = 294.8 mm³ = 0.2948 cm³
2. Calculate the mass of NH₃
?
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