The kitchen drain clogged up again.  There I was sitting on a low stool, peering down through the lifted drain lid into the darkness below, ready to sound the alert, while my mom poured clog removers, sodium bicarbonate, vinegar and hot water into the kitchen sink above, all flushed down with a sound dose of tap water.

  “Here it comes,” I’d announce.  The surface of the water was often dotted with oil droplets, which is a good sign, but seeing them get stranded on piles of…drain mulch as the water receded again was not an appealing sight at all.  My mom used an old chopstick to dig out the soggy mulch and I had the privilege of seeing them up close as she dumped them into the trashcan.  I can’t even begin to guess what all that blackish, slimy muck actually is (or was).

  After several rounds, the clogging seemed to have gotten better, but my mom’s arsenal began to run out.  The bottle of ‘fake’ vinegar ran out, and she began using her own cooking vinegar, but eventually she resorted to just pouring hot water.

  In the end, she finally decided to let the water drain overnight from the pipes so that the clog remover would be actually be able to reach the clogged region.  But dad absent-mindedly turned on the tap late at night to wash his cup, and again in the morning (despite having been told not to), and mom was prepared to give up. 

  She’s called the plumber but he can only make it tomorrow afternoon.  So today, she’s going to work at it again later and hopefully we won’t have to call the plumber.  You bet I’ll be there to serve as watch guard again. *wink*

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Aim: To investigate the effectiveness of different methods in de-clogging a kitchen drain.

Problem statement: What is the most effective way to de-clog a kitchen drain?

Hypothesis: The most effective way to de-clog a kitchen drain is [fill in the blank].

Variables: 

  Manipulated variable: Method used to de-clog the drain.

  Responding variable: Time taken for water in the drain to recede a certain level.

  Fixed variables: Height receded by the drain water, type of sink, length and assembly of the pipes

Materials: cooking vinegar, sodium bicarbonate powder, tap water, clog remover

Apparatus: the kichen sink and its connecting pipes (clogged), toilet pump, kettle, stopwatch

Technique: The time taken for the drain water to recede to a certain level is recorded in order to calculate the rate of de-clogging (ROD).  This will determine the effectiveness of a certain method in de-clogging a kitchen drain.

Procedure:

  1. 100g of clog remover is poured down the kitchen sink followed by 100ml of tap water. 

  2. After 3 minutes, the tap is left to run until the water rises up to the brim on the hole.  The stopwatch is immidiately started.

  3. The stopwatch is stopped once the water recedes round the first bend of the pipe and disappears from view.  The reading is recorded.

  4. Time is turned back until before the start of the experiment.

  5. 100g of sodium bicarbonate powder is poured down the kitchen sink followed by 100ml of vinegar.

  6. Steps 2 to 4 are repeated.

  7. 100ml of tap water is boiled in a kettle and then poured down the kitchen sink.

  8. Steps 2 to 4 are repeated.

  9. While letting the tap run, a toilet pump is used to pump out the clog from the kitchen sink for 3 minutes.

  10. Steps 2 to 4 are repeated.

  11. The results are tabulated in a table and the ROD is calculated as it's reciprocal, s ⁻¹ .

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Oh, the beauties of science (and the eccentricities of its students).