Chemistry part 3

94.1g Ba

A chemical bottle containing BaSO4 is 98.7%. What mass of Ba is present in 162 g of this chemical?

C4H8O2

A compound contains only carbon, hydrogen, and oxygen. Analysis of a sample showed that it contained 54.53% C, 9.15% H and 36.32% O. Its molecular weight was determined to be approximately 88 g/mol. What is its molecular formula?

e. 8

Calcium and chlorine react to form CaCl2, an ionic compound. The chloride ion, Cl-, has _____electrons in its outermost occupied shell. a. 6 b. 2 c. 7 d. 18 e. 8

%K = 56.5% %C = 8.7% %O = 34.8%

Calculate the percent composition of K2CO3.

b. loses three; gains one

Consider the formation of one formula unit of AlF3 from neutral atoms. In the process, each aluminum atom ______ electron(s) and each fluorine atom ______ electron(s). a. gains one; loses three b. loses three; gains one c. loses three; gains three d. gains three; loses one e. loses one; gains three

310 g/mol

Determine the formula weight of Ca3(PO4)2.

d. 2

Draw a Lewis structure for CH3OCH2CH3. What is the total number of lone pair electrons (unshared pair electrons)? a. 3 b. 1 c. 4 d. 2 e. 0

8.57 x10^23

How many atoms of carbon are present is 34.5 g of caffeine, C8H10N4O2?

1.77 x10^23

How many molecules are contained in 5.00 grams of NH3?

0.065mol POCl3

How many moles of POCl3 are there in 10.0g of POCl3?

26

How many valence electrons are present in the Lewis dot formula, ClO3 -

N= 46 A= 32 S= 14e-

In constructing the dot formula for H3AsO4, N=_____, A=_____, and S=______.

c. 8

Magnesium and nitrogen react to form Mg3N2 an ionic compound. The magnesium ion, Mg2+, has _____ electrons in its highest occupied energy level

a. valence shell

The electrons in the outer shell of an atom are involved in bonding. Another name for the outer shell is _____. a. valence shell b. VSEPR shell c. bonding shell d. hybridized shell e. Lewis shell

c. bond length

The internuclear distance at which the attractive and repulsive forces balance in a covalent bond is called the ________. a. single bond b. bond energy c. bond length d. stabilization length e. none of these

c. trigonal planar

What is the electronic geometry for 5 regions of high electron density on a central atom? a. trigonal planar b. octahedral c. trigonal bipyramidal d. tetrahedral e. square planar

d. Ga2Cl3

What is the formula for the binary compound of gallium and chlorine? a. GaCl2 b. Ga3Cl2 c. Ga2Cl3 d. GaCl3 e. GaCl

c. sp

What is the hybridization of a carbon atom involved in a triple bond? a. sp3d b. sp3 c. sp d. sp2 e. sp3d2

26.3g Fe

What mass of iron is contained in 86.6 grams of chalcopyrite, CuFeS2?

a. 2

When you draw a Lewis structure for CH3OCH2CH3, what is the total number of C-C single bonds? a. 2 b. 1 c. 3 d. 4 e. 0

. . d. H : S : (two more dots between S and H) H

Which of the following is the correct Lewis dot formula for H2S?

. . . . e. : Se = C = Se :

Which of the following is the correct Lewis structure for carbon diselenide?

b. KNO3

Which one of the following compounds contains both ionic and covalent bonding? a. MgO b. KNO3 c. HCl d. Rb3N e. CaCl2