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If the empirical formula of a compound is P2O3, and it has a molecular weight equal to 220 g/mol, what is its molecular formula?
When dissolved sodium hydroxide reacts with sulfuric acid, aqueous sodium sulfate, water, and heat are formed.
When isopropanol (C3H80) burns in oxygen, carbon dioxide, water and heat are produced.
Salt is often used to melt ice and snow on roads in the winter and the temperature right now is - 4.500°C. How much NaCl ( complete dissociation) would be necessary to melt 1000kg of ice by bringing down the freezing temperature to 4.500°C?
1. A carbon wire with a 3 mm diameter has a resistance of 100 ohms. How long is the wire?
2. A 200 m long aluminum wire has the same resistance and cross sectional area as a carbon wire. What is the length of the carbon wire?
3. A wire made of an unknown substance has a resistance of 125 mΩ. The wire has a length of 1.8m and a cross-sectional area of 2.35 x 10^-5 m^2. What is the resistivity of the substance from which the wire is made? Give your answer in scientific notation to one dicimal place.
1. To which class does each enzyme belong? Explain your answers.
a.) pyruvate decarboxylase
b.) alanine aminotransferase
c.) alcohol dehydrogenase
d.) hexokinase
1. Consider an example in which 18.0 grams of C6H12O6 is dissolved in 1 kg of water. What is the molality of the resulting solution?
2. What is the mole fraction of sulfur dioxide (SO2) in an industrial exhaust gas containing 128.0 g of sulphur dioxide dissolved in every 1500 g of carbon dioxide?
3. A 123.0 g sample of hardwater is found to contain 0.015 g of calcium carbonate (CaCO3). What is it's concentration in ppm?
Calculate the molarity of a solution containing 2.8 moles of ethyl alcohol (C₂H6O) in 500mL of solution.
What is the molality of 60.5% by mass of nitric acid (HNO3) solution?
What are the mole fractions of hydrochloric acid (HCI) and water in a 20% (w/w) aqeous HCl solution?
