Master Chemistry with Fun Quizzes & Brain Teasers!

a gas mixture containing no2, co2 and so2 occupies 50.0 l at 1.75 atm and 325 k. if there are 37.7 g of no2 in the mixture, what is the mole fraction of no2 and the partial pressure of no2 in this mixture?
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the standard heat of formation for no2 is 33.2kjmol. how much energy is required to form 410.0 g of no2 from its respective elements in kilojoules?
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how would you prepare 1 l of a 0.0500 m phosphate buffer at ph 7.50 using crystalline na2hpo4 and a solution of 1.0 m hcl?
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the natural abundance of calcium in the earth's crust is 3.4% by mass. how many calcium atoms are present in a 1.50 g sample of the earth's crust?
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The isotope calcium-41 decays into potassium-41, with half-life of 1.03 x 105 years. There is a sample of calcium-41 containing 5 x 10 atoms. Howmany atoms of calcium-41 and potassium-41 will there be after 4.12 105 years?A.3.125 x 108 atoms of calcium-41 and 4.375 x 10 atoms of potassium-416.25 x 108 atoms of calcium-41 and 4.6875 x 10 atoms of potassium-416.25 x 108 atoms of calcium-41 and 4.375 10 atoms of potassium-41O D. 3.125 x 108 atoms of calcium-41 and 4.6875 10 atoms of potassium-41
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i can not figure out this question to save my life
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according to the third law of thermodynamics,40)a)the entropy of the universe increases for any spontaneous process.b)energy is conserved in any transformation of matter.c)the entropy of a perfectly ordered, crystalline substance is zero at 0 kelvin.d)the entropy increases for any spontaneous process.
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does a reaction occur when aqueous solutions of calcium chloride and potassium nitrate are combined?
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which metal would you expect to have the highest melting point? which metal would you expect to have the highest melting point? agag tctc rbrb
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the molecular formula for caffeine is c8h10o2n4. how many moles of c atoms are present in a 2.0 g sample of caffeine?
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a chemist adds of a zinc nitrate solution to a reaction flask. calculate the millimoles of zinc nitrate the chemist has added to the flask. round your answer to significant digits.
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this is the chemical formula for talc (the main ingredient in talcum powder): an analytical chemist has determined by measurements that there are moles of magnesium in a sample of talc. how many moles of oxygen are in the sample? be sure your answer has the correct number of significant digits.
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chemical analysis shows that the oxygen-carrying protein hemoglobin is 0.34 percent fe by mass. the actual molar mass of haemoglobin is about 65000g. how many fe atoms are in one molecule of haemoglobin.
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the titration of 19.60 ml of hbr solution of unknown concentration requires 21.06 ml of a 0.100 m koh solution to reach the equivalence point. what is the concentration of the unknown hbr solution in m ?
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what other information do you need in order to determine the molecular formula from the empirical formula of a compound?
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17. Suppose you wish to dissolve non-polar solid iodine. Should you choose water, which ispolar, or liquid bromine, which is non-polar, as the solvent? Explain. A [4 Marks]
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How does the Gulf Stream affect the climate of northern eroupe
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Describe the properties of noble gases. Based on their electronic arrangement
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Where do most rivers begin? In a flat low area or a steep high area?
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Use the diagram to answer the question that follows.Two different samples of matter are measured in each of these glass containers. Both ofthe containers show the same measure for both samples of matter. The samples MOSTlikely have which of these in common
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If you want there to be less of you tomorrow than today... you need to lose
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How many moles of C6H12O6do you have if you have 200 g of C6H12O6?
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Conduct research to learn more aboutthe relative sizes, or atomic radii, of atoms. Find out how scientists define thisproperty, and identify specific examples
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27. Which of the following elements has the greatest electron affinity?berylliumb. neonC fluorined. iridium
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