Greenhouse effect and climate changeIB MYP Chemistry: Mind map

Exam questions on Greenhouse effect and climate change

1. A science teacher in Nairobi explains that, without certain gases in the atmosphere, the average surface temperature of the Earth would be about −18 °C instead of the present 15 °C. Her class is learning which atmospheric gases cause this warming and how they work.
   Explain how greenhouse gases keep the Earth warmer than it would be without them.2 marks
2. Scientists in Antarctica drill ice cores and analyse tiny air bubbles trapped in the ice. Air trapped around the year 1750 contained about 280 parts per million (ppm) of carbon dioxide. A mountain observatory in Hawaii now measures about 420 ppm. Over the same period, global average temperature records show a rise of about 1.1 °C.
   Describe two other types of evidence, apart from the data given, that scientists use to show that the climate is changing.2 marks
3. A student in Singapore investigates whether carbon dioxide traps heat. She fills one clear plastic bottle with air and an identical bottle with air containing extra carbon dioxide from a gas cylinder, and puts a thermometer in each. She shines the same 60 W lamp on both bottles from 30 cm away for 10 minutes and records the temperature each minute. She predicts that the bottle with extra carbon dioxide will warm up more. After 10 minutes, the temperature of the air-filled bottle has risen by 4.0 °C and that of the carbon dioxide bottle by 5.5 °C.
   Identify the independent variable, the dependent variable and one control variable in the student's investigation.3 marks