A solution is prepared by mixing 50.0 mL of 0.50 M Cu(NO3)2 with 50.0 mL of 0.50 M Co(NO3)2. Sodium hydroxide is added to the mi

Answer:

15.71g

Explanation:

The combustion equation that applies to hydrocarbons is

CxHy + (x+y/4) O2 = xCO2 + (y/2) H2O

In the case of octane, C8H18:

C8H18 + ( 8 + 18/4 ) O2 = 8CO2 + 9H2O

C8H18 + 50/4 O2 = 8CO2 + 9H2O

C8H18 + 25/2 O2 = 8CO2 + 9H2O

2C8H18 + 25 O2 = 16 CO2 + 18H2O (this is the balanced equation)

From this balanced reaction,

2 x 22.4 L of octane generates 16 [ 12 + (16 x 2)] of carbon dioxide

That means,

44.8 L of octane generates 704g of carbon dioxide

Thus, for 1L of octane, it produces 1 L x 704g/44.8 L = 15.71g of carbon dioxide

Consequently, 15.71g of carbon dioxide is produced from the complete combustion of 1 L of octane.

Question 1.

The accurate statement is " Aluminium, as it belongs to group 13 and contains three valence electrons. The Lewis dot structure illustrates the number of valence electrons in a single atom. By referencing the periodic table, we identify the element based on its valence electrons. Indeed, aluminium possesses 3 valence electrons and is located in Group 13 of the periodic table.

Question 2.

The correct count is 5. The outer layer of electrons is termed the valence shell, containing what we refer to as valence electrons. Here, the outermost shell corresponds to n=3, meaning all electrons in this layer are classified as valence electrons. While we do have subshells (3s and 3p), they indicate the spatial region where an electron may be located but do not clarify valence.

Question 3.

Chlorine possesses 7 valence electrons, Neon has 8 valence electrons, Phosphorus contains 5 valence electrons, Sulfur has 6 valence electrons. The position of an element in the periodic table aids in determining its electron configuration, and the group number provides insights into the number of valence electrons. By merely checking the periodic table's group number, we can ascertain the valence electrons.

Question 4.

The assertion is True. As atomic orbitals fill, the energy levels extend farther from the nucleus. The outermost orbital capable of being filled with electrons is known as the valence shell, and the electrons within are termed valence electrons. This characteristic defines the reactivity of particular elements.

Question 5.

The atom with the electron configuration contains an unpaired electron in its 3s orbital, rendering it unstable. Meanwhile, the element with 7 valence electrons requires just one additional electron to complete its octet. Therefore, the atom loses an electron to bond with the element holding 7 valence electrons. Consequently, the element acquires a positive charge, while the one with 7 valence electrons becomes negatively charged, leading to the formation of an ionic bond.

Answer:

The molality of the solution is 1.08 m.

Explanation:

First, determine the mass of the solvent.

A 13% solution by mass indicates that 13 grams are found in every 100 grams of solution.

Thus, solution mass = solute mass + solvent mass

100 g = 13 g + solvent mass

Therefore, solvent mass = 100 g - 13 g → 87 g

Next, we calculate the moles of solute (mass / molar mass):

13 g / 138.2 g/mol = 0.094 moles

Finally, to find the molality, which is the moles of solute per 1 kg of solvent (mol/kg), we convert the solvent mass to kg:

87 g. 1 kg / 1000 g = 0.087 kg

Then, molality → 0.094 mol / 0.087 kg = 1.08 m

Answer:

We have 0.29 g of hydrocarbon producing 448ml of CO2 at STP. Therefore, the empirical formula of the hydrocarbon is C2H5, and n equals 2; hence, the molecular formula will be C4H10