A) Suppose you separate a 3.02 g mixture of sand and salt. You recover 1.43 g of salt and 1.41 g of sand. What is the percent recovery of the mixture? B) Suppose you separate a 3.02 g mixture of sand and salt. You recover 1.43 g of salt and 1.41 g of sand. What is the percent recovery of the mixture?
C) Calculate the percent by mass of a solution made from 15 g NaCl (the solute) and 69 g water.
D) What percent of 73.0 g is 26.1 g?

A-B) 94 %.

C) 17.9 %.

D) 35.8 %.

Explanation:

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A-B) In this case, since the total mass of the mixture is 3.02 g and 1.43g+1.41g=2.84 g are recovered in total, we can compute the percent recovery as shown below:

C) Here, since the solution is made up of NaCl and water, we can say that the mass of the solution is 15g+69g=84g; thus, the percent by mass would be:

D) In this case, we simply divide 26.1 g by 73.0 g in order to obtain the percent:

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it is to be noted that an alpha particle is an helium nucleus. so it contains 2 protons 2 neutrons and has a mass number of 4. when alpha decay particles are ejected from the nucleus it gets transformed into an atom which has atomic number less than 2 and a mass number less than 4.

an equation that could represent alpha decay is radium 226 decay of alpha particle forms radon 222.

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in the given question, the partial pressure is calculated by using the ideal gas equation, that is, pv = nrt

here, p is pressure, v is volume = 25 l, n is number of moles = 0.0104 moles, r is gas constant = -0.0821 l.atm / mol.k

t is temperature = 273 k

p = nrt / v

p = (0.0104 mol × 0.0821 l.atm / mol.k × 273 k) / 25 l

= 0.0093 atm