A student investigated the effect of the size of marble chips on the rate of the reaction between marble chips and hydrochloric acid.
This is the method used.
1. Add 10.0 g of marble chips into the flask.
2. Add 50 cm3 of hydrochloric acid and start a timer.
3. Record the mass lost from the flask every 10 seconds.
4. Repeat steps 1 to 3 with different sizes of marble chips.
Figure 1 shows the apparatus.
Which is the independent variable?*
(1 Point)

Given the data below for the reaction, 2 a + 2 b + 4 c => d + e + 3 f, the reaction is fill in the [ ] order in a, fill in the [ ] order in b, fill in the [ ] order in c and fill in the [ ] order overall. (use the words "first, second, third, fourth" to fill each blank)experimentinitial conc of a, mol/l initial conc of b, mol/l initial conc of c, mol/l initial rate, mol/l.s1 0.1 0.1 0.2 2 x 10-32 0.2 0.3 0.2 6 x 10-33 0.3 0.1 0.2 2 x 10-34 0.4 0.3 0.4 1.2 x 10-2