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)

Many free radicals combine to form molecules that do not contain any unpaired electrons. the driving force for the radical–radical combination reaction is the formation of a new electron‑pair bond. consider the chemical equation. n(g)+no(g)⟶nno(g) n(g)+no(g)⟶nno(g) write lewis formulas for the reactant and product species in the chemical equation. include nonbonding electrons. n(g)n(g) select draw rings more erase select draw rings more erase select draw rings more erase n no(g)