Answer:
this can be explained as a non optically active member of a set of stereoisomer, at least two of which are optically active
Explanation:
this means that despite containing two or sterogeonic center the molecules are not chiral
example:
the example above shows at least two choral center and internal mirror plane
Answer: The law of conservation of mass states that, during a chemical reaction, the total mass of the products must be equal to the total mass of the reactants.
Explanation:
Hope it helps
Answer:
The collision of oceanic plates and any other plates in which the oceanic plate slides beneath the other plate creates the biggest earth quakes. Most of these earth quakes occur beneath the sea or oceans and can cause volcanic eruptions as well. Tsunami is another oceanic event that occurs due to earth quakes occurring due to shifting of plates beneath the sea.
Nobles gases, since they all have 8 e- on their last layer of electrons.
Answer: 4.18925 kJ heat is needed to convert 25.0 g of solid ethanol at -135 °C to liquid ethanol at -50°C.
Explanation:
Temperature of Solid
Melting temperature of Solid 
Temperature of liquid 
Specific heats of solid ethanol = 0.97 J/gK
Specific heats of liquid ethanol = 2.3 J/gK
Heat required to melt the the 25 g solid
at 159 K
= 159 K - 138 K = 21 K

Heat required to melt and raise the temperature of
upto 223 K
= 223 K - 159 K = 64 K

Total heat to convert solid ethanol to liquid ethanol at given temperature :
(1kJ=1000J)
Hence, 4.18925 kJ of heat will be required to convert 25.0 g of solid ethanol at -135 °C to liquid ethanol at -50°C.