Answer:
The second on, A man who works as a computer programmer and sits at desk magority of the day.
Explanation:
Answer: Memory B and memory T cells are types of lymphocytes.
Explanation:
Memory B cells forms the part of adaptive immune system. These cells develop inside the germinal centers of the secondary lymphoid organs. These cells circulate in the blood. These are produced by the bone marrow and can be found in tonsil and spleen. Memory B cells are responsible for recognizing previous infections with a foreign antigen and prepare antibody against the new infection. Memory T cells recognize the antigen lived in the body for longer and produce quick response against it on second exposure. These are one of the types of T lymphocytes.
A titration is defined as 'the process of determining the quantity of a substance A by adding measured increments of substance B, the titrant, with which it reacts until exact chemical equivalence is achieved (the equivalence point)'.
The Molarity of the HCl Solution requires the addition of 24.6 mL of titrant is 0.0836 M (to 3 significant figures)
<h3>What is Titrant?</h3>
A reagent solution of precisely known concentration that is added in titration
Given reaction HCl + NaOH ===> NaCl +
neutralization reaction
Note that the mole ratio is 1:1 meaning that 1 mole HCl reacts with 1 mole NaOH to produce 1 mole NaCl and 1 mole 
Find moles of NaOH used:
18.45 ml x 1 L/1000 ml x 0.085 mol/L = 0.002091 moles NaOH used
This meant that there must be 0.002091 moles of HCl present in the 25.0 mls.
We want to find the molarity (M) which is moles HCl/liter of solution. We know the moles, and we also know the liters of solution (25.0 mls x 1 L / 1000 mls = 0.025 liters)
M = 0.002091 moles HCl / 0.025 liters = 0.08364 M = 0.0836 M (to 3 significant figures)
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Given question is incomplete. The complete question is as follows.
Pentaborane (
) is a colorless highly reactive liquid that will burst into flames when exposed to oxygen.the reaction is:
Calculate the kilojoules of heat released per gram of the compound reacted with oxygen.the standard enthalpy of formation
,
, and
are 73.2, -1271.94, and -285.83 kJ/mol, respectively.
Explanation:
As the given reaction is as follows.
Therefore, formula to calculate the heat energy released is as follows.

Hence, putting the given values into the above formula is as follows.

= 
= -9078.59 kJ/mol
Since, 2 moles of Pentaborane reacts with oxygen. Therefore, heat of reaction for 2 moles of Pentaborane is calculated as follows.
= -71.915 kJ/g
Thus, we can conclude that heat released per gram of the compound reacted with oxygen is 71.915 kJ/g.