True/False

I cannot figure this question out. I cannot find any one of these numbers that has 3 significant figures, and when I say that 200 has 1 I get it wrong.

(a) Use the following theoretical density values for copper and zinc metals (in g/mL) and the experimental density values you obtained in Question 12 to determine the percent error in each of your experimental values. Density of copper (theoretical) ρCu = 8.94 g/mL  Density of zinc (theoretical) ΡZn = 7.14 g/mL The equation for percent error is: "%Error"=|"Experimental value - Theoretical value" /"Theoretical value" |×100 Show your work and calculated values, include units. (b) Suggest possible reasons for differences between the experimental and theoretical density values for each metal. 14. Describe any issues you had with the virtual lab, or any unrealistic situations you thought were funny. Also describe the benefits and deficiencies you seen in virtual labs compared to real lab experiences.

Please answer.

How many of the following should be included in a good hypothesis? (1) A prediction of the results of the experiment (ii) A step-by-step walkthrough of how to do the experiment with specific references to amounts of reactants, glassware used, and other experimental details (iii) A summation of the data collected after doing the experiment, with comments on accuracy and precision if possible. (iv) A detailed list of chemicals that will be used (vi) A brief scientific explanation of the predicted results. Said another way, the hypothesis should include a scientific explanation of why the predicted results are expected. (v) Waste disposal procedures 0 1 O 2 O 3 0 4 0 5

True/False Questions. Write False next to the following statements if the statement if false. Write true next to the following statements if the statement is false. 1) Numbers are usually written so that the uncertainty is in the last reported digit. 2) The decimal number 0.0000010 expressed in scientific notation is 1.0 × 106. 3) The decimal number 0.0210 expressed in scientific notation is 2.10 × 10-2, 4) The mass of an object, 4.55 x 10-3 g, expressed in decimal notation is 0.000455 g. 5) Zeros located between two numbers are not significant. 6). The imaginary decimal in the 24500 is located after the 5. 7). Significant figures are important in chemistry because significant figures reflect the degree of precision of the instrument used. 8) Zeros located after a number and after a decimal point are significant. 9) Trailing zeros at the end of a number which does not have a decimal are not significant. 10) The number 0.010100 has five significant figures. 11) The number 4,450,000.0…

After creating her standard curve for absorption versus the concentration (M) of FD&C Red 40 and processing her data, Sally found that her drinking strength Kool-Aid sample had a concentration of 4.692 x 10–5 M. If 0.132 grams of Kool-Aid powder was used to prepare an 8-fl oz cup of her assigned flavor, what is the percent by mass of FD&C Red 40 in her Kool-aid powder? Report your answer as a percentage with two places after the decimal. Do not include the percentage sign in your answer. Pay attention to units. You are trying to find the mass percentage of red dye, so you need to know each variable in the equation in Appendix B. Note that the percent by mass equation should be multiplied by 100. There may be some useful conversion factors in the experimental procedure.

How do I solve this question 40kg/1 × 50mg/1kg × 1mL/100mg × 1teaspoon/5mL

1. A graduated cylinder with a least count of ± 0.5 ml is used in a density experiment. The initial water level, before inserting the irregular shaped solid, is 30.0 ml. After inserting the solid, the water level is 34.5 ml. What is the probable error in the volume of the solid? What is the probable percent error in the volume of the solid?

A chemical industry discharges a waste contaminated with trichloroethylene (TCE) to the city sewer system. By law, the concentration of TCE must be 1 mg/L or less. To enforce this law, the Department of Environmental Conservation (DEC) conducts random testing. The chief environmental engineer for the chemical company knows that the mean TCE concentration in the waste is 0.064 mg/L, and the standard deviation is 0.022 mg/L. The TCE concentration can be assumed to be a normal random variable. What is the probability that the company will fail a random test by the DEC? [In other words, the probability that a random sample will have TCE > 0.1 mg/L.] Show your work and draw a labeled sketch to show what area of the normal distribution curve you used to solve the problem. What is the probability that the company will fail two consecutive random tests? The tests can be assumed to be independent of each other. Show your work. Determine the concentration of TCE that is exceeded only 10%…