The Lewis structure for H₂CO is shown in the attached picture. The central atom is the carbon. However, I'm not sure which bond you're referring to. There can be two answers. The two C-H bonds are sp³ hybridized because it is a single bond. The C=O bond is sp² hybridized because it is a double bond.
To determine the equilibrium concentration of hydronium ions in the solution, we use the given value of the percent ionized. Percent ionized is the percent of the ions that is dissociated into the solution. It is equal to the concentration of an ionized species over the initial concentration of the compound multiplied by 100 percent. For this case, the dissociation of the weak acid has a 1 is to 1 ratio to the ionized species such that the concentration of the CH3COO- and H+ ions at equilibrium would be equal. We calculate as follows:
5.2% = 5.2 M H3O+ / 100 M CH3COOH
5.2 M H3O+ / 100 M CH3COOH = [H3O+] / 0.048 M CH3COOH
[H3O+] = 0.2496 M
Answer: 
Explanation:
The balanced chemical equation :
To calculate the moles, we use the equation:

According to stoichiometry:
4 moles of
produces = 902.0 kJ of energy
415.1 moles of
produces =
of energy
Thus the change in enthalpy is 
First, let's write down the balanced chemical reaction between the given reactants:
NO₂ + NO → N₂O + O₂
The Lewis structure of the main product is shown in the attached picture. To determine the formal charge of each element, the formula is as follows:
Formal Charge = Valence electrons - Non-bonding valence electrons - (Bonding electrons/2)
For the leftmost N:
Formal charge = 5 - 2 - 6/2 = 0
For the middle N:
Formal charge = 5 - 0 - 8/2 = 1
For O:
Formal charge = 6 - 6 - 2/2 = -1
601 expressed as an integer is 3.
An integer refers to a whole number, a number which do not contain any decimal point.
To express any given number as an integer, just count the number of significant figures in the number and write this down as a whole number.