SA1. CHEM. Unit 1 Test

Have you ever made bread before, bread can be baked in loaf pans, baguette pans, or even Dutch ovens like the one shown. Some people might say they place their Dutch oven in their oven at home, or maybe into a campfire. But if they lived in Iceland, they would say they put it in the ground! Locals have been taking advantage of Iceland’s natural hot springs for generations. They bathe in them, harness their energy to power the country, and even cook in them! To bake Iceland’s famous “lava bread,” you simply dig a hole near a hot spring, let the hole fill with the boiling groundwater, place your covered pot inside, cover and mark the hole, and come back the next day for freshly baked bread. This interesting cooking method is not limited to Iceland, however. In the Azores islands, you can cook Cozida das Furnas—a meat and vegetable stew—in hot springs. In Rotorua, New Zealand, food has been boiled and steamed using hot springs for more than 100 years. And tourists in Japan’s Yunomine Onsen can cook their own meal using water from the local hot springs. Which of the following facts could be used in an explanation of why cooking using hot springs is possible? You may choose more than one.

Place the statements in the correct order of events that explains how energy is transferred during the baking of lava bread

Dutch ovens come in two main forms: the traditional Dutch oven and the French oven. Both are circular pots with tightfitting lids, but the traditional Dutch oven is made only of cast iron and the French oven is cast iron coated in enamel. Regardless of their differences, the two types of Dutch ovens use the same method to transfer thermal energy from their surroundings to the food inside of them. We can measure the amount of thermal energy that is transferred in a system using the formula. Plan an experiment to prove that energy will flow from water into an object or from an object into water. Explain what quantitative data you would collect and how you would analyze your data. How could your data help you determine if the reaction was endothermic or exothermic?

Select and change words in this text to accurately describe how energy flows through a Dutch oven and how much energy will be needed to bake bread given the following circumstances:

• In order for the dough to bake, it should be at a temperature of about 100°C for around 12 hours.

• The Dutch oven in question is 6,350 g.

• Assume the Dutch oven began at room temperature: 20°C.

• The specific heat of cast iron is 0.46 J/g°C.

The heat from Earth’s mantle provides a great source of thermal energy, but it can be used for so much more. Scientists have been unsuccessfully trying to bore into the mantle since the 1960s to learn more about Earth’s past, present, and future. If we can make it into the mantle, we can collect more accurate data about the movement of the mantle and its makeup. Right now, our knowledge of the mantle is limited to what we’ve learned from the movement of earthquake waves through the earth and samples that are launched from volcanoes. Some of the factors keeping us from reaching the mantle are the sheer depth we would have to go and the heat and pressure that are present at those depths.

1. Engineers can solve big problems by breaking them into smaller, more manageable problems. Which small problems were addressed by the different pieces of this solution?

2. What are some of the issues this solution could have in terms of cost, safety, reliability, and environmental impact?

Solution: One solution to entering Earth’s mantle could be a sphere containing a GPS device and covered in several layers of hafnium carbide—a metal with a melting point of nearly 4,000°C. The device will have an inner layer of osmium, which is twice as dense as lead. It will be dropped inside of an undersea volcano. Its density should cause it to sink through the magma and to the mantle, and its protective layer should keep it from being destroyed by the heat. As the device sinks and moves through the mantle, it will send off periodic pings of the GPS to track its location. This will allow scientists to track the movement of Earth’s mantle.