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
As the temperature increases, B) the molecules started moving faster.
Explanation:
The temperature of a substance is a measure of the average kinetic energy of the particles in a substance. In particular, it can be found that the temperature is directly proportional to the average kinetic energy of the particles:
The kinetic energy of a particle is given by
where
m is the mass of the particle
v is its speed
This means that the higher the temperature of a substance, the greater the speed of the particles in the substance.
Therefore, if we apply this concept to this problem, we infer that as the temperature of the water in the pond gets higher, the speed of the molecules inside the water increases, which means that the molecules are moving faster.
Therefore, the correct answer is
B) the molecules started moving faster.
Learn more about temperature:
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