1 mol of formic acid is correct. There are two oxygen atoms in formic acid, compared to just one for the other molecules.
8) The gravitational force is a force of attraction between two objects. It can be expressed mathematically as:
F = G m₁*m₂/d² ------(1)
m₁ and m₂ are the masses of two interacting systems
d = distance between them
G = gravitational constant
Thus according to equation(1), the gravitational force is directly proportional to the mass of the objects. Greater the masses, stronger will be the force of attraction.
In this case, the distance (d) and the one of the masses i.e. mass of earth would be the same for both situations. However, since an elephant would weigh more than a human, the gravitational force will be stronger between an elephant and earth.
9) Since the masses of spheres is the same, the gravitational force between the red and blue spheres would be the same as well, provided the distance d remains constant.
In a closed system, as energy is transformed, it is neither lost nor created. Rather, energy is conserved. Is the force that one surface exerts on another surface when two surfaces rub against each other. When parts of a moving system encounter friction, some of the kinetic energy is transformed into thermal energy.
Part (a): The masses
From the periodic table:
molar mass of copper = 63.5 grams
This means that:
mass of 2..06 moles = 2.06 * 63.5 = 130.81 grams
comparing this mass with the 222 grams of silver, we will find that the mass of silver is greater.
Part (b): The atoms:
number of moles = mass / molar mass
number of moles of silver = 222 / 107.8 = 2.059 moles
each mole contains Avogadro's number of atoms.
Since number of moles of copper is slightly larger than nuber of moles of silver, this means that the number of atoms in the copper sample would be more.
