Chapter 1, Problem 1.93AE

The present average concentration (mass percent) of magnesium ions in seawater is 0.13%. A chemistry textbook estimates that if 1.00 × 108 tons Mg were taken out of the sea each year, it would take one million years for the Mg concentration to drop to 0.12%. Do sufficient calculations to either verify or refute this statement. Assume that Earth is a sphere with a diameter of 8000 mi, 67% of which is covered by oceans to a depth of 1 mi, and that no Mg is washed back into the oceans at any time.

1 A student mixes 1.0 mL of aqueous silver nitrate, AgNO3 (aq), with 1.0 mL of aqueous sodium chloride, Nacl (aq), in a clean test tube. What will the student observe? A silver mirror will coat the interior of the test tube. Bubbles will form within the liquid mixture. The mixture will remain colorless and transparent. The mixture appears to be white and cloudy. The mixture will remain colorless and transparent, but the test tube will feel hot.

At a certain temperature, an aqueous solution is 16.5% K2CO3 by mass and has a density of 1.149 g/cm3. What is the molarity of the solution?Provide your answer with 3 significant figures.

If we have a salt solution with a density of 1.2g/cm^3 and a metal bar with a density of 8.96g/cm^3, which one occupies a larger volume if we have 100g of each substance? I got that salt had a volume of 83ml and copper of 11.16ml. Why does the salt take up more volume? Doesn't it dissolve in the water?

In a flask, you heat a mixture of 735.4 g of sodium nitrate and 700.0 grams of water until all of the sodium nitrate has just been dissolved. At what temperature does this occur? When you examine the solution later, the temperature is 25°C and you notice a white powder in the beaker. What has happened? What is the mas of the white powder? Solubility vs. Temperature 140 KI 130 120 NaNO, gases 110 sólids 100 KNO, 90 80 HCI NH,CI 70 60 NH3 KCI 50 40 NacT 30 KCIO, 20 10 SO2 0 10 20 30 40 50 60 70 80 90 100 Temperature °c Solubility (grams of solute/100 g H2O)

A geochemist measures the concentration of salt dissolved in Lake Parsons and finds a concentration of  25.·gL−1 . The geochemist also measures the concentration of salt in several nearby non-isolated lakes, and finds an average concentration of  4.2·gL−1 .   Assuming the salt concentration in Lake Parsons before it became isolated was equal to the average salt concentration in nearby non-isolated lakes, calculate the percentage of Lake Parsons which has evaporated since it became isolated. Round each of your answers to  2  significant digits.

Most analytical machines used in science can either measure absorbance of light, like the spectrophotometers used BioZ 151 and 152 labs, or can measure change in electrical conductance. In order to convert things like absorbance values into concentration data, a linear regression is used. In order to determine nitrite concentration in water samples, nitrite is reacted with several chemicals to produce a purple color. The absorbance of the solution is measured from known amounts of nitrite to produce a standard curve to analyze samples. Use the data in the provided table, or from the linked spreadsheet to make a graph and perform a linear regression using treadline. mg/L NO3 Absorbance 0 0.1 0.3 0.5 0.7 o 0.183 0.542 0.914 1.298) 1.61) In order for this to work, samples must be diluted prior measurement so that the concentration falls within the range of the standard curve. If a sample underwent a 30 dilution, and produce an absorbance value of 0.953, what is the resultant concentration…

A sample of an ethanol-water solution has a volume of 54.4 cm^3 and a mass of 49.9 g. What is the percentage of ethanol (by mass) in the solution? (Assume that there is no change in volume when the pure compounds are mixed.) The density of ethanol is 0.789 g/cm^3 and that of water is 0.998 g/cm^3.

You perform your first titration using your NaOH with a KHP solution. Your KHP solution is made with 0.5045 g of KHP. The initial amount of NaOH in your pipette is 16.26 mL and the final amount in your buret is 36.79 mL when the indicator changes colour. Determine the concentration of your NaOH solution. Write your answer to four decimal places without units.