Concept explainers
a)
Interpretation: Among below experiments I, II, III and IV; experiments that yield same average result should be determined.
Concept introduction:Any test, trial or tentative procedure that is executed under highly controlled conditions whose purpose is to examine validity of any hypothesis is called an experiment. These are also performed so as to discover unknown things in nature.
Below mentioned are some of the essential features of a well-designed experiment.
1. Experiment should be designed in such a way that it can be repeated to have same results.
2. Such variables should be used in experiments that can be easily controlled and manipulated directly or indirectly by the performer.
3. Atleast two relatable variables should be present in experiment.
b)
Interpretation: Among below experiments I, II, III and IV; experiments that displayhigh precision should be determined.
Concept introduction:Any test, trial or tentative procedure that is executed under highly controlled conditions whose purpose is to examine validity of any hypothesis is called an experiment. These are also performed so as to discover unknown things in nature.
The closeness of measurements with each other is termed as precision. It determines the extent to which measurements are close to each other.
c)
Interpretation: Among below experiments I, II, III and IV; experiments that display high accuracy should be determined.
Concept introduction:Any test, trial or tentative procedure that is executed under highly controlled conditions whose purpose is to examine validity of any hypothesis is called an experiment. These are also performed so as to discover unknown things in nature.
The extent to which calculated or measured values are close to standard one is called accuracy.
d)
Interpretation: Among below experiments I, II, III and IV; experiments that show systematic error should be determined.
Concept introduction:Any test, trial or tentative procedure that is executed under highly controlled conditions whose purpose is to examine validity of any hypothesis is called an experiment. These are also performed so as to discover unknown things in nature.
Errors in any measurement can be either random or systematic. These are mentioned below.
1. Systematic errors: Such errors arise due to faulty experimental set or equipment.
2. Random errors: These occur due to precision of the instruments.
Want to see the full answer?
Check out a sample textbook solutionChapter 1 Solutions
Principles of General Chemistry
- The label on a bale of mulch indicates a volume of 1.45 ft3. The label also states that the mulch in the bale will cover an area of a garden 6 ft 6 ft to a depth of 1 in. Account for the discrepancy in the given volumes.arrow_forwardMolecular distances are usually given in nanometers (1 nm = 1 109 m) or in picometers (1 pm = 1 1012 m). However, the angstrom () unit is sometimes used, where 1 = 1 1010 m. (The angstrom unit is not an SI unit.) If the distances between the Pt atom and the N atom in the cancer chemotherapy drug cisplatin is 1.97 , What is this distances in nanometers? In picometers?arrow_forwardWhich of the following represent physical properties or changes, and which represent chemical properties or changes? You curl your hair with a curling iron. You curl your hair by getting a “permanent wave” at the hair salon. Ice on your sidewalk melts when you put salt on it. A glass of water evaporates overnight when it is left on the bedside table. Your steak chars if the skillet is too hot. Alcohol feels cool when it is spilled on the skin. Alcohol ignites when a flame is brought near it. Baking powder causes biscuits to rise.arrow_forward
- In the following scenario, identify which of the statements represents a theory, law, or hypothesis. (a) A student exploring the properties of gases proposes that is she decreases the volume of a sample of gas then the pressure exerted by the sample will increase (b) Many scientists over time have conducted similar experiments and have concluded that pressure and volume are inversely proportional. (c) She proposes that the reason this occurs is that if the volume is decreased, more molecules will collide with a given area of the container walls, causing the pressure to be greater.arrow_forwardA student determined in a set of four experiments that the density of magnesium metal was 1.66 g/ml,1.65 g/ml, 1.67 g/ml, 1.67 g/ml. The accepted value for its density is 1.72 g/ml. What can you concludeabout the precision and accuracy of the student’s data?arrow_forwardThe density of a certain metal is (6.60x10^0) g/cm3. What is the mass in grams of a sample of this metal that has a volume of (8.460x10^-2) m3? Enter your answer in scientific notation with 3 sig figs. Do not include any units in your answer. Do not round any intermediate calculations. Note: Your answer is assumed to be reduced to the highest power possible. Your Answer:arrow_forward
- The following statements pertain to the development of the theory of combustion by the French chemist Lavoisier in the eighteenth century. Match the statement with the appro- priate step (observation, hypothesis, experiment designed to test hypothesis) in the scientific method. (a) A metal is burned in a closed container, and the change in mass of the solid and volume of the gas is measured.(b) Oxygen gas combines with a substance during its combustion.(c) Combustion of a metal in a closed container ceases after a length of time.arrow_forwardThe accepted value of the melting point of pure aspirin is 135 °C. Trying to verify that value, you obtain 134 °C, 136 °C, 133 °C, and 138 °C in four separate trials. Your partner finds 138 °C, 137 °C, 138 °C, and 138 °C. (a) Calculate the average value and percent error for your data and your partner’s data. (b) Which of you is more precise? More accurate?arrow_forwardTake the mass measurement with nitrogen (28 dalton or atomic mass units per molecule) and the mass measurement with helium (4 daltons per atom) and use the difference between the measured masses to find the mass of 1 dalton (one atomic mass unit) in grams. The standard value of the dalton is 1.66053906660×10−27 kg with an uncertainty of ±50 in the last two figures. Can you identify the sources of error in your measurement?arrow_forward
- Imagine that have a cube of iron metal that you know has a mass of exactly 1.0000 grams because the cube was calibrated before you purchased it. You carefully measure the mass of this cube several times using the balance in your lab, but every time the balance indicates that the cube has a mass of 1.0900 grams. (i) State whether this balance be considered to be accurate, precise, both, or neither and (ii) explain how you made your choice.arrow_forwardA student gently drops an object weighing 16.5 g into an open vessel that is full of ethanol, so that a volume of ethanol spills out equal to the volume of the object. The experimenter now finds that the vessel and its contents weigh 10.5 g more than the vessel full of ethanol only. The density of ethanol is 0.789 g / cm^3. What is the density of the object?arrow_forwardDashboard My Home OWLV2 | Online teaching and learning resource from Cengag [References) A student gently drops an object weighing 15.7 g into an open vessel that is full of ethanol, so that a volume of ethanol spills out equal to the volume of the object. The experimenter now finds that the vessel and its contents weigh 10.6 g more than the vessel full of ethanol only. The density of ethanol is 0.789 g/cm°. What is the density of the object? Density = g/cm³ Submit Answer Try Another Version 10 item attempts remainingarrow_forward
- Chemistry & Chemical ReactivityChemistryISBN:9781337399074Author:John C. Kotz, Paul M. Treichel, John Townsend, David TreichelPublisher:Cengage LearningChemistry: The Molecular ScienceChemistryISBN:9781285199047Author:John W. Moore, Conrad L. StanitskiPublisher:Cengage LearningIntroductory Chemistry: A FoundationChemistryISBN:9781337399425Author:Steven S. Zumdahl, Donald J. DeCostePublisher:Cengage Learning
- Chemistry & Chemical ReactivityChemistryISBN:9781133949640Author:John C. Kotz, Paul M. Treichel, John Townsend, David TreichelPublisher:Cengage Learning