If 20.0g of MgSO4⋅7H2O is thoroughly heated, what mass of anhydrous magnesium sulfate will remain?

The response is:

No, the equation is not balanced. Neither the Nitrogen (N) nor the Hydrogen (H) are in balance!

Here's the reasoning:

⓵ A properly balanced chemical equation means that the quantity of atoms on the reactants side matches that on the products side.

→ The equation lacks balance because there are 2 Nitrogen atoms and 2 Hydrogen atoms on the reactants side. In contrast, on the products side, there is only 1 Nitrogen atom and 4 Hydrogen atoms. Thus, the number of atoms on each side is not consistent!

Hopefully, this clarification is helpful; feel free to reach out if you have any further questions! ☻

The interaction between calcium carbonate and hydrochloric acid can be represented by the chemical equation,

    CaCO3 + 2HCl --> CaCl2 + H2O + CO2

Calcium carbonate has a molecular weight of 100 g/mol, while hydrochloric acid's molecular weight is 36.45 g/mol. According to the equation, 100 g of calcium carbonate reacts with 72.9 g of hydrochloric acid.

    x = (4 g HCl)(100 g CaCO3 / 72.9 HCl)
      x = 5.49 g

Final result: 5.49 g

The mass of KBr required is 16.7 g. This concludes from a volume of 0.400 L and a concentration of 0.350 M. Utilizing the molarity formula, moles are calculated as 0.14, leading to a molecular weight calculation of 119 g/mol, thus resulting in a mass of 16.7 g of KBr.

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:

No

Explanation:

When heated, tin could react with alkali metals, releasing hydrogen gas.