Density=mass/volume
Data:
mass=890 g
volume=100 cm³
Density=890 g/100 cm³=8.9 g/cm³
answer: the density of the copper is 8.9 g/cm³
<span>What all chemical reactions have in common is that energy is released in various forms. Sometimes it's heat or light when there's an explosion, or theres gas and odors or a change in color, or sometimes solids are formed as a deposit. This all show that a reaction occurred and are used as proof.</span>
The electric potential due to ammonia at a point away along the axis of a dipole is 1.44 
10^-5 V.
<u>Explanation:</u>
Given that 1 D = 1 debye unit = 3.34 × 10-30 C-m.
Given p = 1.47 D = 1.47 3.34 10^-30 = 4.90 10^-30.
V = 1 / (4π∈о) (p cos(θ)) / (r^2)
where p is a permanent electric dipole,
∈ο is permittivity,
r is the radius from the axis of a dipole,
V is the electric potential.
V = 1 / (4 3.14 8.85 10^-12) (4.90 10^-30 1) / (55.3 10^-9)^2
V = 1.44 10^-5 V.
Answer: Thus 44 g of 
will be produced if 30 g of 
were reacted with an excess of oxygen
Explanation:
To calculate the moles :
The balanced chemical equation is:
As is the limiting reagent as it limits the formation of product and 
is the excess reagent.
According to stoichiometry :
1 mole of produce = 6 moles of
Thus 0.17 moles of will produce=
of
Mass of 
Thus 44 g of will be produced if 30 g of were reacted with an excess of oxygen.
