Why is each year's vaccine different?

Chemistry

2 answers:

Degger [83]3 years ago

5 0

Because the birds that fly overseas carry different flu viruses every year.

Gemiola [76]3 years ago

5 0

Answer:

Flu vaccinations are needed each year to ensure you have continuous protection. Though you may have received a flu vaccine last year, your body's immune system from previous vaccinations gradually decreases over time. By the time flu season comes around, your body's immunity to it is virtuality non-existent.

Explanation:

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g A spontaneous process is one in which: A. releases a large amount of heat B. may happen (is possible) C. will rapidly approach

katrin2010 [14]

Answer:

A. releases a large amount of heat

Explanation:

A reaction is said to be spontaneous if it can proceed on its own without the addition of external energy. A spontaneous reaction is not determined by the length of time, because some spontaneous reactions are completed after a long period of time. They are exothermic in nature. An example is the conversion of graphite to carbon which takes a long period of time to complete. Spontaneous reactions are known to increase entropy in a system. Entropy is the rate of disorder in a system.

In the combustion of fire, energy is released to the surroundings as there is a decrease in energy. This is an example of a spontaneous reaction because it is an exothermic reaction, which causes an increase in entropy and a decrease in energy.

7 0

3 years ago

Suppose a 0.025M aqueous solution of sulfuric acid (H2SO4) is prepared. Calculate the equilibrium molarity of SO4−2. You'll find

FromTheMoon [43]

<u>Answer:</u> The concentration of $SO_4^{2-}$ at equilibrium is 0.00608 M

<u>Explanation:</u>

As, sulfuric acid is a strong acid. So, its first dissociation will easily be done as the first dissociation constant is higher than the second dissociation constant.

In the second dissociation, the ions will remain in equilibrium.

We are given:

Concentration of sulfuric acid = 0.025 M

Equation for the first dissociation of sulfuric acid:

$H_2SO_4(aq.)\rightarrow H^+(aq.)+HSO_4^-(aq.)$