Practical Detection Questions and Answers

Calcium hydride combines with water according to the equation: CaH₂(s) + 2H₂O() → 2H₂(g) + Ca(OH)₂(s) Beginning with 84.0 g of CaH₂ and 42.0 g of H₂O, what volume of H₂ will be produced at 273 K and a pressure of 1327 torr?

Calculate the volume in milliliters of a 0.876M zinc nitrate solution that contains 250. mmol of zinc nitrate digits. (Zn(NO₂)₂) Round your answer to 3 significant

A chemist has a block of aluminum metal (density is 2.7 g/mL). They drop the metal into a graduated cylinder containing water, and find the volume change is 2.3 mL. What is the mass of the block, in grams?

A chemist adds 35.0 mL of a 0.191 mol/L barium chlorate (Ba(ClO3)2) solution to a reaction flask. Calculate the millimoles of barium chlorate the chemist has added to the flask. Round your answer to 3 significant digits.

Fill in the missing symbol in this nuclear chemical equation.

A chemist must dilute 35.2 mL of 5.36 M aqueous zinc nitrate water to the solution until it reaches a certain final volume. Calculate this final volume, in milliliters. Round your answer to 3 significant digits. (Zn(NO3)₂) solution until the concentration falls to 2.00 M. He'll do this by adding distilled

In a titration experiment in which a standard solution of hydrochloric acid is being added to a sodium hydroxide solution to determine the concentration of the sodium hydroxide solution, the end point is when The liquid in the burette is reduced to half of the original volume All of the standard hydrochloric acid solution is used up All of the liquid is the burette is used up All of the sodium hydroxide has reacted

There are limitations to the amount of pressure that can be applied during reverse osmosis because of the physical nature of the membrane. A membrane has been developed that can withstand osmotic pressures, II, of up to 1.54x105 torr. Calculate the maximum molar concentration of a solution that can be purified by reverse osmosis using this membrane at 25 °C. Express your answer with the appropriate units.

A sample of sodium reacts completely with 0.568 kg of chlorine, forming 936 g of sodium chloride. What mass of sodium reacted? Express your answer to three significant figures and include the appropriate units.

Determine the empirical formula of an oxide for Silicon based on the following data. Mass of empty crucible and lid - 23.4428 g Mass of crucible, lid, and Silicon - 36.1028 g Mass of crucible, lid, and the oxide formed - 50.5271 g Show detailed calculations Format Table

Which changes are evidence of a chemical reaction? Drag each item to the appropriate bin. ►View Available Hint(s) A beaker of water becomes cool to the touch upon adding a salt to it. Bubble formation on chalk added to acid Evidence Ethanol evaporating Reset Help Bubbles forming in a shaken water bottle Two cloudy solutions are mixed and become clear. Not evidence

In a lab, silver nitrate, AgNO3, is dissolved in water until no solid is observed in the container. Then, a solution of sodium chloride, NaCl, is added to the container. When you combine these aqueous solutions, there is no noticeable change in temperature; however, a solid precipitates and there is a slight change of color. Which statements about the lab experiment involving silver nitrate and a sodium chloride solution are true? Drag each item to the appropriate bin. ► View Available Hint(s) Formation of a solid indicates a chemical reaction occurred. The initial disappearance of silver nitrate in water indicates a chemical reaction occurred. The lack of temperature change indicates a chemical reaction didn't occur. True Reset hemical reaction occurred when silver nitrate was added to water. The color change of the solution indicates a chemical reaction occurred. A chemical reaction did occur when the solutions were combined. False Help