Answer:
a. True
Explanation:
Molecule -
- It refers to a group of two or more than two atoms , which can exists freely on it own , is referred to as a molecule .
- The molecule is a neutral group , where the atoms are bounded by chemical bonds .
- Molecule have a characteristic property of the substance.
Hence, the given statement about molecule , is true.
Answer: 0.74 moles
Explanation:
The first step is to figure out the chemical formula for calcium phosphate. Since we know that calcium is a metal, this will be an ionic bond. Calcium is written as Ca and has a charge of +2. Phosphate is written as PO4 with a charge of -3. To come up with the subscripts for this formula, cross the charges. That means that you will get 
.
Next, calculate how many grams one molecule of calcium is. Calcium has an atomic weight of 40, and there are 3 molecules of calcium, so 40 x 3 = 120. Phosphorus has an atomic weight of 31, and there are 2 molecules of phosphorus, so 31 x 2 = 62. Oxygen has an atomic weight of 16, and there are 8 molecules of oxygen, so 16 x 8 = 128. Adding all of those together gives you 310 g.
Now, using stoichiometry, we can figure out the question. We know that there are 230 grams. We also know that one mole weighs 310 g. If you divide 230 by 310, you will get your answer, which is 0.74 moles.
Answer:
The energy need to break this 0=0 bond is 495 kJ/mol
Explanation:
Step 1: Data given
oxygen molecule = O2
In an O2 molecule, the 2 O-atoms are held together by a double bond with a bond energy of 495 kJ/mol.
To break this chemical bound, it requires energy
2O(g) → O2(g)
The bound energy of a double oxygen bound = 495 kJ/mol
Since we have 1 molecule (consisting in 2 O atoms)
The energy need to break this 0=0 bond is 495 kJ/mol
Answer:
1) first order
2) second order
3) zero order
Explanation:
The curve of a first order reaction shows it to be exponential. In fact for a first order reaction, the concentration at a time t is an exponential function;
[A]t= [Ao] e^-kt
Where
[A]t = concentration at time =t
[Ao]= initial concentration
k= rate constant
t= time
For a second order reaction, the rate of reaction is directly proportional to the concentration of reactants.
For zero order reactions, rate of reaction is independent of concentration hence rate = k(rate constant)
