Mole/molarity/empirical formula

One mol of particles of any substance contains how many particles?

6.022 × 10²³

The empirical formula of a compound is CH2, and its molar mass is about 42g. What is its molecular formula?

C3H6

How many moles of CaCl2 are in 250. mL of a 3.00 M of CaCl2 solution?

0.750 mol

What is the molar mass of lactic acid, C3H6O3?

90.08 g

How many atoms of potassium are in 0.250 mol of potassium carbonate, K_2 CO_3?

3.01 × 10²³ atoms

What is the molarity of the solution obtained when 0.100 mol of copper sulfate are dissolved in 0.200 liters of solution?

0.500 M

What is the molar mass of copper (ll) sulfate, CuSO4?

159.62 g

What is the mass of 0.00100 mol of caffeine, C8H10N4O2?

0.194 g

What is the molar mass of Mg3(PO4)2, a substance formerly used in medicine as an antacid?

262.9 g

Calculate the empirical formula of a compound that has a composition of 5.9% (by mass) hydrogen and 94.1% (by mass) oxygen.

HO

When 100. mL of 6.00 M HCI is diluted to 300. mL, the final concentration is ________.

2.00 M

Calculate the molarity of the solution formed when of 50.0 g of the non electrolyte glucose (Molar mass 180.2) is dissolved in 0.250 kg water.

1.11 molal

When is the empirical formula of the compound between calcium and sulfur that has the percent composition 55.6% (by mass) calcium and 44.4% (by mass) sulfur?

CaS

A sample of a white solid contains 0.212 g of magnesium and 0.140 oxygen. What is the empirical formula of this compound?

MgO

Calculate the molarity of 60.05 g of acetic acid, HC2H302, dissolved in 0.250 L of solution.

4.00 M

1.00 mol of neon has a mass of ______.

20.2g

How many mL o 1.24 M H2SO4 reacts with 1.26 g of Al?

2Al(s)+3H2SO4(aq)→Al2(SO4)3(aq)+3H2(g)

56.5 mL

How many atoms of chlorine are in 1.00 mol of chlorine gas (Cl_2)?

1.20 × 10²4

What is the mass percent (m/m) concentration of a solution prepared from 500. g NaCl and 2.50 kg of water?

16.7%

How many carbon atoms are there in 1.00 mol of C2H6?

1.20 × 10²^4