What do you know about reactions?
Have a go!A. Answer these questions about the following equation: 
H2(g)   +  Cl2(g)  =  2HCl(g)  DH = -184 kJ mol-1
Click the radio button next to the answer you think is correct.
1. What does the number 2 in front of the HCl mean?
number of atoms of hydrogen number of moles of hydrogen
number of atoms in hydrogen chloride number of moles of hydrogen chloride
2. The (g) means
gaseous geothermal
gravitational gasiform
3. In a hydrogen molecule there are two atoms of hydrogen.

True

False
4. In a hydrogen chloride molecule there are two atoms.

True

False
B. Chemical reactions
1.Chemical reactions require energy changes.

True

False
2. The dissolving of a solute involves energy changes. True

False
3. The dissolving of a solute is an example of a chemical reaction.
(You may wish to discuss this with your colleagues and teacher.). 		True

False
C. Covalent bonds
1. A covalent bond is holding atoms together in a molecule. True

False
2. A covalent bond is holding atoms together in an ionic crystal   structure. True

False
3. A covalent bond is a weak bond. True

False
4. Substances with covalent bonds have high melting points True

False

(attempted  maximum 11)

The rest of this set of activites will help you understand the meaning of the part of the equation: DH = - 184 kJ mol-1  Go to the first activity
 

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