Mixture Problem A jeweler has five rings, each weigh - ing 18 g, made of an alloy of 10% silver and 90% gold. She decides to melt down the rings and add enough silver to reduce the gold content to 75%. How much silver should she add?

Calculate the ratio of effusion rates between helium and radon gases

What is the role of the sun in the water cycle

The enthalpy of formation of water is - 285.8 kJ/mol. What can be inferred from this statement? A. The enthalpy of the products is equal to the enthalpy of the reactants. B. Heat is absorbed during the process. C. Heat is released during the process.

A piece of charcoal used for cooking is found at the remains of an ancient campsite. a 0.94 kg sample of carbon from the wood has an activity of 1580 decays per minute. find the age of the charcoal.

Given that the molar mass of NaCl is 58.44 g/mol, what is the molarity of a solution that contains 87.75 g of NaCl in 500. mL of solution? moles of solute Use molarity - liters of solution

What is the nearest star in Gemini

In order for a solute to dissolve in a solvent, what must be true?

Radiocarbon dating can be used to determine the age of A a sample less than a million years old B a sample less than 100,000 years old C a sample less than 50,000 years old - D a sample less than five million years old

How many electrons in an atom can have each of the following quantum number or sublevel designations? (a) 4p (b) n = 3, l = 1, m1 = + 1 (c) n = 5, l = 3

Could the two aqueous solutions be identified through a visual inspection? Explain.