Choose the chemical equation that is correctly balanced. 2Ca(s) + Cl2(g) → CaCl2(s) 4Mg(s) + O2(g) → 2MgO(s) Li(s) + Cl2(g) → 2LiCl(s) C(s) + O2(g) → CO2(g)

Last option C(s) + O2(g) → CO2(g)

Explanation:

The reactions are:

2Ca(s) + Cl2(g) → CaCl2(s)

4Mg(s) + O2(g) → 2MgO(s)

Li(s) + Cl2(g) → 2LiCl(s)

C(s) + O2(g) → CO2(g)

Let's count the atoms (check out the stoichiometry):

1. We have 2 Ca in reactant side and 2Cl, in product side we have 1 Ca and 2 Cl. UNBALANCED

2. We have 4 Mg in reactant side and 2 O. In product side we have 2 Mg and 2 O. UNBALANCED

3. In reactant side we have 1 Li and 2 Cl. Then, in product side we have 2Li and 2Cl. UNBALANCED

C(s) + O2(g) → CO2(g)

1 C and 2 O ⇒ 1 C and 2 O         Correctly balanced

1. 1 mole of anything contains 6.022x10^23 pieces  

d  

2. a  

3. c, number  

5. 1.24x10^24atoms / 6.022x10^23atoms/mole = 2moles h2 atoms  

6. fe2br3 mass = 2moles x mass fe + 3 moles x mass br  

molar mass = grams / number of moles = g/mole  

to find moles = g / molar mass  

to find mass = g = molar mass / moles

conduction is the transfer of thermal energy (heat in transfer) due to collisions between the molecules in the object. collisions between adjacent atoms and molecules transfer kinetic energy from the warmer to the cooler object. the objects must be in physical contact.