Answer:
Earthquakes are measured using instruments called seismometers, that detect the vibrations caused by seismic waves as they travel through the crust. Also, laser beams can be used
Explanation:
Answer:
See explanation
Explanation:
Polymerization is the process whereby two or more monomers link together to form a compound of high molecular mass called a polymer.
There are two kinds of polymers;
-Addition polymers
-Condensation polymers
Addition polymers are formed by the joining of two or more monomers to form a polymer without the elimination of a small molecule.
Condensation polymers are formed by the joining of two or more molecules to form polymers with the elimination of a small molecule.
The main difference between polyethene and polyester is that polyethene is an addition polymer while polyester is a condensation polymer.
In polyethene, ethene molecules are joined together having the repeating unit as [-CH2-CH2-]n.
In polyester, the polymer arises from the reaction of carboxylic acid and an alcohol and loss of water molecules.
Answer:
1, 3, 2
Explanation:
N2 + H2 → NH3
I usually find that the best way to systematically balance an equation by inspection is to start with the most complicated-looking formula and then balance atoms in the order:
- All atoms other than O and H
- O
- H
(a) The most complicated formula is NH3.
(b) Balance N.
We have 1 H in NH3, but 2 N on the left. We need 2 N on the right. Put a 1 in front of N2 and a 2 in front of NH3.
1N2 + H2 → 2NH3
(c) Balance H.
We have fixed 6 H on the right, so we need 6 H on the left. Put a 3 in front of H2.
1N2 + 3H2 → 2NH3
The equation is now balanced, and the coefficients are 1, 3, 2.
Answer:
75 kJ/mol
Explanation:
The reactions occur at a rate, which means that the concentration of the reagents decays at a time. The rate law is a function of the concentrations and of the rate constant (k) which depends on the temperature of the reaction.
The activation energy (Ea) is the minimum energy that the reagents must have so the reaction will happen. The rate constant is related to the activation energy by the Arrhenius equation:
ln(k) = ln(A) -Ea/RT
Where A is a constant of the reaction, which doesn't depend on the temperature, R is the gas constant (8.314 J/mol.K), and T is the temperature. So, for two different temperatures, if we make the difference between the two equations:
ln(k1) - ln(k2) = ln(A) - Ea/RT1 - ln(A) + Ea/RT2
ln (k1/k2) = (Ea/R)*(1/T2 - 1/T1)
k1 = 8.3x10⁸, T1 = 142.0°C = 415 K
k2 = 6.9x10⁶, T2 = 67.0°C = 340 K
ln(8.3x10⁸/6.9x10⁶) = (Ea/8.314)*(1/340 - 1/415)
4.8 = 6.39x10⁻⁵Ea
Ea = 75078 J/mol
Ea = 75 kJ/mol
