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CHECKING YOUR UNDERSTANDING OF CLAY CHEMISTRY
TUTORIAL #1: Part 2
Last updated August 17, 2012

Below are some questions regarding Tutorial #1: Part 2: Clay Chemistry for CHM-107 (Lecture)

Copy the questions below (highlight the text, then press the CTRL key plus "c", or use the Edit menu at top and choose "Copy")

In your email program start composing an email and paste the questions to your email. You can then answer them in your email and send to chm107pc@gmail.com
Question 1: If this woman was to leave the grain outside for a few days, what might happen to it? (other than someone stealing it)
Question 2: In the past, it was common for families to can their food. "Canning" meant to place in sterilized jars. Why did people "can" their food?

Question 3: Pottery was able to keep out rodents, which are notorious for chewing through things. The lower incisor teeth shown grow 1 millimeter (1 mm) per day. How many inches a year do these teeth grow? Figure 365 days in a year. One inch = 25.4 millimeters.

Question 4: As other materials were added to clay and the temperatures of firing got hotter, more durable and waterproof pottery was made. The plate on the right is bone china. Why is it called bone china and is it a high or low quality pottery? You can use the link below for answers if you want.

Link to info about stoneware and fine china

Question 5: Earthenware is clay fired at a low kiln temperature around 1400-2000°F . Earthenware is not very strong and is porous.
Stoneware - harder than earthenware, stoneware is fired at about 2200-2400°F. Stoneware is strong and can hold water, though is not completely water proof unless glazed.
Porcelain - a special type of clay either white or grey, to which kaolin (a white firing stiff clay) and white China stone (finely decayed granite) is added. When fired at temperatures of 2300°F and over (up to 2550°F was achieved by the Chinese), the body vitrifies, i.e. it becomes glass-like and completely impermeable.
If your oven was capable of heating up to 2400°F (1315°C), what metals in your oven would have melted? Let's say there were aluminum, iron, chromium, and copper used in your oven.
(hint: search for "melting point metals").
Question 6: On the right are formulas for four different clays. What three elements are found in each of these clays? Also, notice that "talc" is a clay. You know it as the main ingredient in talcum powder; however, being a clay, talc can be heated to make porcelain-like dinnerware. They call it steatite porcelain. Sometimes these formulas are written to show the water, for example, kaolinite is also written Al2O3·2SiO2·2H2O. The element count is the same, but you can better see the water (H2O) that will be driven off upon heating.


Question 7: Instead of pottery, clay is also used to make bricks. Why do you think there is a lot of smoke coming from this brick factory in Vietnam?

 
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