General Chemistry Answers

What volume did a helium-filled balloon have at 26.8 °C and 1.87 atm if its new volume was 63.2 mL at 2.22 atm and 9.6°C? O a. 79.6 O b. 209 O c. 70.7 O d. 56.5

Application of Charles’ Law can be seen as one flies in a hot air balloon, when heated, causes the air to expand; thus, becomes lighter and so it rises. Which of the following is another application of Charles’ Law?

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1 point

AgF(aq) + Fe(CO3)3(aq)

Which compound when dissolved in water will turn blue litmus paper red?

a. H2O (l)

b. BaCI2 (aq)

c. HClO (aq)

d. NH4OH (aq)

Calcium carbide (CaC2) reacts with water to produce acetylene (C2H2) and calcium hydroxide. If 5.50 mol calcium carbide reacts with an excess of water, how many moles of acetylene will be produced?

How do you get the volume of HCl and Volume of gas in a flask using a mass HCl of 53.23 g and Density HCl of 1.05 g/mL

What is the oxidation number nitrogen in PB(NO₃)₂

Chemist to determine copper concentration in rock sample. Knowing copper undergoes redox reactions, they chose to use iodometric titration for analysis. Unknown sample weighing 1.5098g was acidified with 3.0M H2SO4 to dissolve copper compounds and diluted with 30mL distilled water. This was followed by addition of excess KI producing I2 and CuI precipitate from Cu2+(Reaction 1). Then, liberated I2 reacted with excess KI forming triiodide anion(Reaction 2), which was titrated with Na2S2O3 titrant(Reaction 3). This entire solution required 17.60 mL of titrant to reach starch end point.

MW: Cu (63.546)

a. Write balanced chemical equation for Reactions 1-3

b. Write mole ratio between Cu2+ and S2O32–

Prior to titration of sample, titrant was standardized by taking 50.0 mL of 6.7863x10-3M standard KIO3 solution, acidifying, and adding KI crystals. Titration of this solution required 9.80mL to reach starch endpoint.

c. Write concentration of S2O32– titrant in M

d. Write copper content of rock sample in %w/w

why is it that when you try to boil an egg in an open pot, and leave awhile, upon returning you've noticed the water decreases? what about the movement of water molecules? what if you decided to put a lid on the pot, what will be the movement of the water molecules?

What is the weight percent (w/w) of NaOH in a solution prepared by dissolving 30.0g of NaOH in 120.0g of H₂O?