Question

Use the equation and the table to answer the question. FeCl3 + 3H2O → Fe(OH)3 + 3HCl Element Mass of an Atom (amu) Fe 56 Cl 35 H 1 O 16 Iron chloride and water react according to the equation shown. The table shows the atomic masses of the elements involved in the reaction. What is the total mass of the reactants? (1 point) Responses 215 amu 215 amu 179 amu 179 amu 161 amu 161 amu 108 amu 108 amu Skip to navigation

Answer 1

To find the total mass of the reactants in the given reaction:

\[ \text{FeCl}_3 + 3\text{H}_2\text{O} \rightarrow \text{Fe(OH)}_3 + 3\text{HCl} \]

we first need to calculate the mass of each reactant based on the given atomic masses.

1. Iron chloride (FeCl3):

   • 1 Fe atom = 56 amu
   • 3 Cl atoms = 3 × 35 amu = 105 amu
   • Total mass of FeCl3 = 56 amu + 105 amu = 161 amu

2. Water (H2O):

   • 2 H atoms = 2 × 1 amu = 2 amu
   • 1 O atom = 16 amu
   • Total mass of H2O = 2 amu + 16 amu = 18 amu

Now, we can calculate the total mass of the reactants:

\[ \text{Total mass of reactants} = \text{mass of FeCl}_3 + \text{mass of 3H}_2\text{O} \] \[ \text{Total mass of reactants} = 161 \text{ amu} + 3 \times 18 \text{ amu} \] \[ \text{Total mass of reactants} = 161 \text{ amu} + 54 \text{ amu} = 215 \text{ amu} \]

So, the total mass of the reactants is 215 amu.

Answer 2

In a chemical reaction, two molecules with a total mass of 76 amu react to form a single molecule. What is the mass of the molecule that is formed?(1 point) Responses 76 amu 76 amu 38 amu 38 amu 228 amu 228 amu 152 amu

Answer 3

In a chemical reaction, the law of conservation of mass states that the total mass of the reactants must equal the total mass of the products.

Given that the two molecules have a total mass of 76 amu, the mass of the single molecule formed as a product will also be 76 amu.

Therefore, the mass of the molecule that is formed is 76 amu.

Answer 4

Which statement about an atom is correct?(1 point) Responses The electron has a negative charge and is found outside of the nucleus. The electron has a negative charge and is found outside of the nucleus. The neutron has no charge and is found outside of the nucleus. The neutron has no charge and is found outside of the nucleus. The neutron has a negative charge and is found in the nucleus. The neutron has a negative charge and is found in the nucleus. The proton has no charge and is found in the nucleus. The proton has no charge and is found in the nucleus.

Answer 5

The correct statement about an atom is:

The electron has a negative charge and is found outside of the nucleus.

Electrons are subatomic particles that carry a negative charge and are located in the electron cloud surrounding the nucleus of the atom.

The other statements provided are incorrect:

• Neutrons have no charge, but they are found inside the nucleus (not outside).
• Neutrons do not have a negative charge; they are neutral.
• Protons have a positive charge, not no charge, and they are found inside the nucleus.

So the first option is the correct answer.

Answer 6

Cobalt has a mass number of 59 and an atomic number of 27. A student wants to create a model of a cobalt atom. Which statement about the model is correct?(1 point) Responses The model should show 27 protons and 32 neutrons. The model should show 27 protons and 32 neutrons. The model should show 59 protons and 27 neutrons. The model should show 59 protons and 27 neutrons. The model should show 27 protons and 27 neutrons. The model should show 27 protons and 27 neutrons. The model should show 32 protons and 59 neutrons. The model should show 32 protons and 59 neutrons.

Answer 7

To determine the correct statement about the model of a cobalt atom, we need to understand the relationship between the atomic number, mass number, protons, and neutrons.

• The atomic number (27) represents the number of protons in the atom.
• The mass number (59) represents the total number of protons and neutrons in the atom.

To find the number of neutrons, we can use the following formula:

\[ \text{Neutrons} = \text{Mass number} - \text{Atomic number} \] \[ \text{Neutrons} = 59 - 27 = 32 \]

So, cobalt has:

• 27 protons
• 32 neutrons

The correct statement about the model is:

The model should show 27 protons and 32 neutrons.

Answer 8

Question In a molecule of lithium sulfide, there are two atoms of lithium and one atom of sulfur. Which statement about lithium sulfide is correct?(1 point) Responses A molecular model of lithium sulfide would have two spheres. A molecular model of lithium sulfide would have two spheres. Both lithium and sulfur form positive ions. Both lithium and sulfur form positive ions. The chemical formula for lithium sulfide is LiS2. The chemical formula for lithium sulfide is LiS 2 . The atoms in lithium sulfide are held together by bonds. The atoms in lithium sulfide are held together by bonds.

Answer 9

To analyze the statements about lithium sulfide (Li\(_2\)S), we need to consider its composition and bonding:

1. Lithium (Li) is an alkali metal that typically forms a positive ion (Li\(^+\)).
2. Sulfur (S) is a non-metal that typically forms a negative ion (S\(^{2-}\)).

Given these points, let's evaluate each statement:

1. A molecular model of lithium sulfide would have two spheres.

   • This is incorrect because the model would actually involve more atoms than just two spheres since it contains two lithium atoms and one sulfur atom.

2. Both lithium and sulfur form positive ions.

   • This is incorrect. Only lithium forms positive ions (Li\(^+\)), whereas sulfur typically forms negative ions (S\(^{2-}\)).

3. The chemical formula for lithium sulfide is LiS\(_2\).

   • This is incorrect. The correct formula is Li\(_2\)S, indicating two lithium atoms for each sulfur atom.

4. The atoms in lithium sulfide are held together by bonds.

   • This is correct. The atoms in lithium sulfide are held together by ionic bonds, formed between the positively charged lithium ions and the negatively charged sulfide ions.

Therefore, the correct statement about lithium sulfide is:

The atoms in lithium sulfide are held together by bonds.

Answer 10

Use the periodic table to answer the question. Which element has the same number of valence electrons as bromine (Br)? (1 point) Responses krypton (Kr) krypton (Kr) chlorine (Cl) chlorine (Cl) selenium (Se) selenium (Se) potassium (K) potassium (K) Skip to navigation

Answer 11

Bromine (Br) is in Group 17 of the periodic table, which means it has 7 valence electrons.

To find the element that has the same number of valence electrons (7) as bromine, let's evaluate the options provided:

1. Krypton (Kr): Group 18 (Noble gases), has 8 valence electrons.
2. Chlorine (Cl): Group 17, has 7 valence electrons.
3. Selenium (Se): Group 16, has 6 valence electrons.
4. Potassium (K): Group 1, has 1 valence electron.

The correct answer is:

Chlorine (Cl), as it has the same number of valence electrons (7) as bromine (Br).