Chem- Chapter 1 Homework
A container was found in the home of the victim that contained 121 g of ethylene glycol in 540 g of liquid. What was the percentage of ethylene glycol?
22% 121/54= .224 = 22% The concentration of ethylene glycol in the liquid can be expressed in a variety of ways. Dividing the mass of ethylene glycol by the total mass of the liquid yields the mass ratio, 0.224. The mass ratio is a decimal number, which is then converted to the mass percentage by multiplying it by 100%.
A collection of coins contains 11 nickels, 6 quarters, and 5 dimes. What is the percentage of dimes in the collection?
23% 11+6+5=22 5/22= .227 = 23%
A container was found in the home of the victim that contained 120 g of ethylene glycol in 600 g of liquid. How many drinks, each containing 100 g of this liquid, would a 60 kg victim need to consume to reach a toxic level of ethylene glycol?
5 drinks You can find the toxic level (or lethal dose) by multiplying the mass of the person by 1.5 g/kg body mass, which yields 90.0 g of ethylene glycol. The concentration is used as a conversion factor to calculate how much ethylene glycol is in each drink, which contains 100 g of the liquid. 120g ethylene glycol600g liquid×100 g liquid=20.0g ethylene glycol Lastly, dividing the lethal dose by the mass of ethylene glycol in each drink yields how many drinks the person must consume to reach that toxic level.
A clinic had 25 patients on Friday morning. If 15 patients were given flu shots, what percentage of the patients received flu shots?
60 % 15/25=.6=60%
An alloy contains 59 g of pure silver and 18 g of pure copper. What is the percentage silver in the alloy?
77 % 59+18=77 59/77= .766 = 77%
You've asked your friends to define the terms "chemistry" and "chemical." With which definitions do you agree?
Chemistry is the study of the composition, structure, properties, and reactions of matter. A chemical is a substance that has the same composition and properties wherever it is found.
ucia wants to develop a process for dyeing shirts so that the color will not fade when the shirt is washed. She proceeds with the following activities: A. Lucia notices that the dye in a design fades when the shirt is washed. B. Lucia decides that the dye needs something to help it combine with the fabric. C. She places a spot of dye on each of four shirts and then places each one separately in water, salt water, vinegar, and baking soda and water. D. After one hour, all the shirts are removed and washed with a detergent. E. Lucia notices that the dye has faded on the shirts in water, salt water, and baking soda, while the dye did not fade on the shirt soaked in vinegar. F. Lucia thinks that the vinegar binds with the dye so it does not fade when the shirt is washed.
Observation AE Hypothesis B Experiment CD Conclusion F
Identify each of the following as an observation, a hypothesis, an experiment, or a conclusion:
observation Drinking coffee at night keeps me awake. hypothesis If I stop drinking coffee in the afternoon, I will be able to sleep at night. experiment I will try drinking coffee only in the morning. conclusion
Identify each of the following as an observation, a hypothesis, an experiment, or a conclusion: Nurses make observations in the hospital.
observation During an assessment in the emergency room, a nurse writes that the patient has a resting pulse of 30 beats/min. hypothesis A nurse thinks that an incision from a recent surgery that is red and swollen is infected. experiment conclusion Repeated studies show that lowering sodium in the diet leads to a decrease in blood pressure.
Obtain a bottle of multivitamins and read the list of ingredients. What are four chemicals from the list?
vitamin A vitamin B6 vitamin B3 vitamin C
