Question

Answer these questions about the substance given by the formula CBr₄:

a.) Classify the substance: is it an element, a compound, a homogenous mixture, or a heterogeneous mixture?
b.) If the substance is an element, is it a metal, nonmetal, or a metalloid?
c.) If the substance is a compound, is it an ionic compound or a molecular compound?
d.) What is the name of the substance?
e.) What is the mass of a mole of the substance?
f.) In 10.0g of the substance, how many atoms are found? How many molecules? How many cations? How many anions? Express your answers to the proper number of significant digits.
g.) Do all the atoms or ions in the substance contain the same number of protons? If they do, how many are in each atom or ion? If they do not, what are the different numbers of protons?

Answer 1

a) This is a single entity composed of different atoms, so it is a compound.

b) -

c) It is a molecular compound.

d) It is called tetrabromomethane.

e) A mole has the mass of 1 mole of C + 4 moles of Br, this is:

$m=12\frac{g}{mol}+4\cdot 79.9\frac{g}{mol}=295.6\frac{g}{mol}$

f) If 295.6 grams are 1 mole, this means that there are 6.022x10²³ molecules in that mass. By using cross multiplication we can calculate the number of molecules in 10.0 g:

$n_{molecules}=\frac{6.022x10^{23}\: molecules}{295.6g}\cdot 10.0g=2.04x10^{22}\: molecules$

And since in each molecule there are 5 atoms, the total number of atoms is:

$n_{atoms}=5\cdot 2.04x10^{22}=1.02x10^{23}\: atoms$

Since this is not an ionic compound, there are no cations or anions present.

g) There are no protons in the given compound.