Answer:
The smell of a chocolate is from the presence of volatile compounds present in the chocolate bar which at room temperature readily changes phase from solid to liquid to vapor or gas
Explanation:
There are nearly 600 identified compounds present in a chocolate bar and out of these, there are volatile components which gives the chocolate bar its distinctive aroma.
These volatile chocolate contents readily change phase from solid to vapor, with very short duration liquid phase.
For example, 3 methylbutanal, vanillin, and several organic compounds which are known to be readily volatile.
<span>Avogadro's number
represents the number of units in one mole of any substance. This has the value
of 6.022 x 10^23 units / mole. This number can be used to convert the number of
atoms or molecules into number of moles. We do as follows:
4.50 mol Fe ( 6.022x10^23 atoms / 1 mol Fe ) = 2.71x10^24 atoms Fe present </span>
Answer:
are gases at room temperature
usually do not react with other elements
are in a group called the noble gases
are nonmetals
Explanation:
The elements in group 18 or group O are the inert elements. They have completely outermost shell and are not reactive. Every atom reacts with another in order to be like the noble gases.
- All of the elements here are gaseous.
- They do not readily react with other elements.
- They are called noble gases, inert gases, or group O elements.
It should be noted that group 17 elements are very reactive compared to the group O elements.
Answer:They are not permanently altered by the reaction they catalyze.
Explanation: Enzymes are usually in lower concentration than substrate molecules they catalyze. Hence an enzyme catalyzes as many substrate molecules as it can. So when an enzyme binds a substrate to it's active site, it does this so as to increase the reaction rate which otherwise would not have been possible without the enzyme. It doesn't mean that the enzyme itself takes part in the chemical reaction. Hence, once an ES(Enzyme-substrate) moves to P(product), the product leaves the active site and the enzyme returns to it's original confirmation ready for binding another molecule of the substrate. Therefore, the enzyme is altered transiently in order to allow the substrate fit into it's active site. Its never altered permanently
<span>The balanced chemical equation for this reaction is:
2NaOH (aq)+H2SO4 (aq) → Na2SO4 (aq)+2H2O (l)
According to question, 60 ml of NaOH solution was used for neutralizing 40 ml of 0.50M H2SO4.
The no. of moles of H2SO4 is calculated using the equation:
mol solute = (molarity) (L soln)
mol H2SO4 = 0.50 M x 0.040 L = 0.02 moles of H2SO4
As per the equation, the number of moles of NaOH used is:
0.02 moles of H2SO4 (2 mol NaOH) (1 mol H2SO4) = 0.04 moles of NaOH
Therefore, using the given volume of NaOH, the concentration or molarity of NaOH can be calculated using the formula :
Molarity = mol solute/L soln = 0.04 mol NaOH/0.06 L = 0.67 M
Therefore, the concentration of NaOH is 0.67 M.</span>
