How many moles are in 8.11 X 1020 molecules of CH4?

What is the formula mass for sodium chloride?

Zigmanuir [339]

Atomic mass of sodium is 22.9 g/mol
atomic mass of chloride is 35.45 g/mol
sodium chloride is 22.99 + 35.45= 58.44 g/mol

3 0

3 years ago

_____ bonds are formed when the electronegativity difference is 0.4 > 2.0. Give two examples:

34kurt

Ionic Bond is formed when the electronegativity difference is 0.4 > 2.0. Electronegativity is a term that can be defined as a tendency of an atom to attract electron towards its own self.

Explanation:

Electronegativity is a term that can be defined as a tendency of an atom to attract electron towards its own self.

An electronegativity of an atom is affected by

The atomic number of the atom
Secondly by the distance at which the valence electron are residing from the nucleus

1. In case the electronegativity difference (which is denoted by ΔEN) is less than 0.5 then the bond formed is known as Nonpolar covalent.

2. In case the ΔEN is in between 0.5 and 1.6, the bond formed is referred to as the Polar covalent

3. In case the ΔEN is more /greater than 2.0, then the bond formed is referred to as Ionic Bond

2 Examples of Ionic bonds

The formation of sodium fluoride, NaF, from a sodium atom and a fluorine atom is an example of Ionic bond formation.
Another example is the formation of NaCl from sodium (Na),which is a metal, and chloride (Cl), which is a nonmetal

6 0

3 years ago

What is the mass of an electron?

Lesechka [4]

Answer:

the answer is 0 amu I hope it helps

6 0

3 years ago

How many atoms of hydrogen are in ethanol (C2H5OH)?

EleoNora [17]

So we have: 1 C2H5OH + _ O2 -> 2 CO2 + _ H2O Step 3: The only molecule on the right that is left is H2O. We start with 6 hydrogen atoms on the left.

6 0

3 years ago

Calculate the pH of: (a) 0.1M HCl; (b) 0.1M NaOH; (c) 3 X 10% M HNO3; (d) 5 X 10-10 M HCIO.; and (e) 2 x 10-8 M KOH.

Shtirlitz [24]

Answer:

(a) $pH = -Log (0.1M) = 1$

(b) $pH = -Log (10^{-13}M) = 13$

(c) $pH = -Log (3x10^{-3}M) = 2.5$

(d) $pH = -Log (4.93x10^{-10}M) = 9.3$

(e) $pH = -Log (5^{-7}M) = 6.3$

Explanation:

To calculate de pH of an acid solution the formula is:

$pH = -Log ([H^{+}]) = 1$

were [H^{+}] is the concentration of protons of the solution. Therefore it is necessary to know the concentration of the protons for every solution in order to solve the problem.

(a) and (c) are strong acids so they dissociate completely in aqueous solution. Thus, the concentration of the acid is the same as the protons.

(b) and (e) are strong bases so they dissociate completely in aqueous solution too. Thus, the concentration of the base is the same as the oxydriles. But in this case it is necessary to consider the water autoionization to calculate the protons concentration:

$K_{w} =[H^{+} ][OH^{-}]=10^{-14}$