Gc Pro Profs Quiz Chapter 7 (Sections 1-3)

In this compound, Ba(C2H3O2)2, there are two acetate ions (C2H3O2-) present. Each acetate ion contains two carbon atoms. Therefore, the total number of carbon atoms in the compound is 4.

The correct answer is Cu+2. The formula for the copper (II) ion is Cu+2, indicating that it has a charge of +2. This means that copper has lost two electrons, resulting in a positive charge. The Roman numeral II in the name indicates the charge of the ion.

The total net charge of MgO is 0 because MgO is an ionic compound consisting of magnesium (Mg) and oxygen (O). Magnesium has a charge of +2, while oxygen has a charge of -2. In order to balance the charges and form a neutral compound, one Mg ion with a charge of +2 combines with one O ion with a charge of -2, resulting in a total net charge of 0.

The molar mass of barium hydride, BaH2, can be calculated by adding the atomic masses of barium (Ba) and hydrogen (H) in the compound. The atomic mass of Ba is 137.33 g/mol, and the atomic mass of H is 1.01 g/mol. Therefore, the molar mass of BaH2 is (137.33 g/mol) + 2(1.01 g/mol) = 139.35 g/mol. To find the mass of 5 moles of BaH2, we multiply the molar mass by the number of moles: 5 mol x 139.35 g/mol = 696.75 g. Rounding to the nearest tenth, the mass is 696.7g.

The charge on a platinum (IV) ion is +4. This is because the Roman numeral IV indicates that the platinum ion has a charge of +4. Roman numerals are commonly used in chemistry to indicate the oxidation state or charge of an ion. In this case, the +4 charge indicates that the platinum ion has lost four electrons and has a positive charge of four.

The correct answer is 65.57%. This means that in FeCl3, 65.57% of the compound is made up of chlorine (Cl).

The oxidation number of Pb in PbCl4 is +4. This is because chlorine (Cl) has an oxidation number of -1, and there are four chlorine atoms in PbCl4. Since the overall charge of PbCl4 is neutral, the sum of the oxidation numbers must be zero. Therefore, the oxidation number of Pb can be calculated as (+4) + 4(-1) = 0, resulting in Pb having an oxidation number of +4.

The molar mass is equal to the formula mass. Molar mass is the mass of one mole of a substance, and it is calculated by summing up the atomic masses of all the atoms in the substance's chemical formula. This includes all the atoms present in the formula, regardless of the number of atoms or the type of element. Therefore, the correct answer is formula mass, as it represents the molar mass of a substance.

Cyanide (CN) is a negatively charged ion with a charge of -1. This means that it has gained one electron, giving it an overall negative charge. The charge of -1 indicates that cyanide has one more electron than protons, resulting in a net negative charge.

To find the molar mass of any compound, you need to determine the number of atoms of each element in the compound. Then, you multiply that number by their average atomic masses (represented by red numbers) and add them together. This calculation allows you to determine the total mass of one mole of the compound, which is its molar mass.

The correct answer is "All of the above." This is because 6.022x10^23 is a significant number on the mole map, known as Avogadro's number. It represents the number of molecules or particles per one mole of a compound or atom. Therefore, all the statements mentioned in the answer options are true.

The molar mass of C6H12O6 (glucose) is 180.18 g/mol. To find the mass of 0.75 moles of C6H12O6, we can multiply the molar mass by the number of moles: 0.75 mol * 180.18 g/mol = 135.14 g. Therefore, the correct answer is 135.14g.

The percent composition of a compound is the percentage by mass of each element in the compound. In H2SO4, there are 2 hydrogen atoms out of a total of 7 atoms. To calculate the percent composition of hydrogen, we divide the number of hydrogen atoms by the total number of atoms in the compound and multiply by 100. Therefore, the percent composition of H in H2SO4 is 2%.

A bromine ion has a charge of -1 and is called bromide. This means that bromine has gained one electron, resulting in a negative charge.

The chemical formula for Calcium Hydroxide is Ca(OH)2. Calcium Hydroxide is composed of one calcium ion (Ca2+) and two hydroxide ions (OH-). The subscript 2 in the formula indicates that there are two hydroxide ions for every calcium ion.

In a binary compound, the cation (positively charged ion) is always listed first, followed by the anion (negatively charged ion). This is because the cation is the element that loses electrons and becomes positively charged, while the anion is the element that gains electrons and becomes negatively charged. Therefore, the correct order for the parts of a binary compound is cation, anion.

The correct chemical formula for Chromium(III) Sulfate is Cr2(SO4)3. This is because the Roman numeral III in parentheses after Chromium indicates that it has a +3 charge. Sulfate (SO4) has a -2 charge. To balance the charges, we need two Chromium ions (Cr3+) to combine with three Sulfate ions (SO4^2-), resulting in the formula Cr2(SO4)3.

In H2SO4, the oxidation number for hydrogen is +1 and the oxidation number for sulfur is +6. Since the compound is neutral, the sum of the oxidation numbers must be zero. Therefore, the oxidation number for oxygen can be calculated as follows: 2(+1) + x + 4(-2) = 0, where x represents the oxidation number for oxygen. Simplifying this equation gives: 2 + x - 8 = 0. Solving for x, we find that the oxidation number for oxygen is -2.

Aluminum sulfate has the chemical formula Al2(SO4)3. This means that there are two aluminum atoms in one molecule of aluminum sulfate. Therefore, the correct answer is 2.

The correct answer is calcium. This is because the chemical formula Ca(NO3)2 indicates that the salt contains the cation, or positively charged ion, of calcium (Ca). The other options, nitric acid, nitrous acid, and oxygen, are not present in the salt's formula.

In a polyatomic ion, the total sum of the oxidation numbers equals the charge that is on the ion. This is because the oxidation number represents the charge that an atom would have if electrons were transferred completely. Therefore, when all the oxidation numbers of the atoms in a polyatomic ion are added together, it will equal the overall charge of the ion.

The correct answer is Fe(NO2)2. Iron (II) Nitrite is formed by combining the iron (II) cation (Fe2+) with the nitrite anion (NO2-). Since the iron (II) cation has a +2 charge and the nitrite anion has a -1 charge, two nitrite ions are needed to balance the charge, resulting in the chemical formula Fe(NO2)2.

To find the number of moles of a compound, we need to divide the given mass of the compound by its molar mass. The molar mass of K2Cr2O7 can be calculated by adding the atomic masses of its constituent elements. The molar mass of K2Cr2O7 is 294.18 g/mol. Dividing 20.0 g by 294.18 g/mol gives us approximately 0.068 moles. Therefore, the correct answer is 0.068.

Oxidation numbers are a concept used in chemistry to track the movement of electrons during a chemical reaction. They indicate the hypothetical charge an atom would have if all the bonds were 100% ionic. However, oxidation numbers do not directly correspond to any physical property, such as bond length, polarity, or size of the atom. Instead, they are a purely theoretical construct that helps chemists understand and predict the behavior of elements in compounds.