This may help you
Allright for <span><span>H2</span>O:</span>
- The central atom is? --> the oxygen atom
- How many atoms are bonded to the central atom? --> 2 hydrogen atoms
- How many lone pairs of electrons are on the central atom? --> O has 6 electrons and has 2 single bonds, so 2 pairs
- How many single bonds are there in this molecule? --> 2
- How many multiple bonds (double and/or triple) are there in this molecule? --> none
For each of your molecules, answer the following questions:
1. Determine the electronegativity between the atoms of each molecule.
Electronegativity O = 3.44
Electronegativity H = 2.20
3.44-2.20=1.24, so the electronegativity between O and H = 1.24
2. Identify the bond as either ionic or covalent.
Electronegativity of 0.0-1.7 = covalent
Electronegativity of 1.7-3.3 = ionic
So it's a covalent bond
3. State whether the molecule is polar or non polar.
Electronegativity of 0.5-1.7= polar covalent
4. Identify the structure as having hydrogen bonding, dipole-dipole moments or London dispersion forces (LDF).
<span><span>H2</span>O</span><span> = hydrogen bonding</span>
As size increases<span> or decreases, </span>DENSITY REMAINS THE SAME<span>! As a rule, things that are MORE dense will sink or fall to the bottom of things that are LESS dense (think of oil and water). ... Notice that </span>if<span> you DECREASE the </span>mass<span> of something or</span>INCREASE<span> the </span>volume<span>, the </span>density<span> will be less…</span>
Answer:
For a volume of 1 liter, we have a total mass of 220 grams of CaCl2 ( Option A)
Explanation:
<u>Step 1: </u>Given data
The concentration of the solution we want to make is 2M
2M = 2 moles/ L So the volume = 1L
The molar mass of CaCl2 is = 40 + 2*35 = 110g/mole
<u>Step 2:</u> Calculate number of moles
If we consider the volume = 1 L then for a concentration of 2M, this means the number of moles is 2
<u>Step 3:</u> Calculate mass
The molar mass of CaCl2 = 110 g/mole
This means 110 grams per 1 mole
for 2 moles the mass is 220 grams
This means that for a volume of 1 liter, we have a total mass of 220 grams of CaCl2
To determine the amount of oxygen that is present in the compound, we have to assume that the given compound contains carbon, hydrogen and oxygen only or else we will not be able to determine the answer. We need to convert the moles of the elements given to units of grams by using the atomic mass of these elements. Then, from the total amount of the compound we subtract the masses of the elements. We do as follows:
mass
0.117 mol C ( 12.01 g / 1 mol ) = 1.41 g
0.233 mol H ( 1.01 g / 1 mol ) = 0.24 g
Mass O = 3.50 g - 1.41 g - 0.24 g = 1.85 g O
Moles O = 1.85 g O ( 1 mol / 16 g ) = 0.116 moles O
Answer:
Electrolytes are substances that can ionize in water. They could be acids, bases or salts as long as they give ions when they dissolve in water.
Explanation:
- <em>Strong electrolytes</em> completely ionize when dissolved in water, leaving no neutral molecules. The strong electrolytes here are:<u> salt water</u>, <u>baking soda (NaHCO3) solution.</u>
- <em>Weak electrolytes</em> do not completely dissociate in solution, and hence have a low ionic yield. Examples of this would be<u> vinegar </u>and <u>bleach </u>(which could be sodium hypochlorite or chlorine, which are weakly dissociated).
- <em>Non-electrolytes </em>will remain as molecules and are not ionized in water at all. In this case, <u>sugar solution is a non-electrolytes</u>, even though sugar dissolves in water, but it remains as a whole molecule and not ions.
