Answer:10^27 atoms in an apple
Explanation:
Answer:
9.6 %
Explanation:
<u>Step 1: How to define percent error ? </u>
⇒ % error is the difference between a measured value and the known or accepted value
⇒Percent error is calculated using the following formula:
⇒%error = | Experimental value-theoretical value/theoretical value | x100%
⇔ this can be written as well as : error = (| Experimental value/ theoretical value | - | Theoretical value / Theoretical value | ) x100%
<u>Step 2: Calculate % error</u>
In this case, this means :
%error = ( |(4.45 cm - 4.06cm ) / 4.06cm | ) x100%
%error = 0.096 x100%
%error =9.6 %
DeltaH formation = deltaH of broken bonds - deltaH of formed bonds
Broken bonds: tiple bond N-N and H-H bond
Formed bonds: N-H and N-N bonds
You also have to take note of the molar coefficients
deltaH formation = <span> [(N≡N) + 2 * (H-H)] - [4 * (N-H) + (N-N)]
= (945 + 2*436) - (4*390 + 240)
= 17 kJ/mol
The answer is 17 kJ/mol.</span>
The elements in the periodice table are not listed in alphabetical order, because the arragement in rows (periods) and columns (groups or familes), in increasing order of atomic number (number of protons of the atoms) permits to explain similarities among the elements, trend in some properties, and even predict properties of unknown elements.
For example, the elements of the first group (family), called alkaline metals, all have 1 valence electron, have similar physical properties (ductibility, malleability, luster, thermal and electricity conductivity), react in similar way with water, show a trend in the atomic radii and in the ionization energy.
You can tell similar stories for other groups like, alkalyne earth metals, halogens and noble gases.
You can also tell trends in electroneativities, and atomic radii, for a row of elements, as per the order they are in the row.
So, the current array resulted very helpul for chemists to explain and predict the behavior and properties of the elements.
Answer:
a. Methanol remains the same
b. Methanol decreases
c. Methanol increases
d. Methanol remains the same
e. Methanol increases
Explanation:
Methanol is produced by the reaction of carbon monoxide and hydrogen in the presence of a catalyst as follows; 2H2+CO→CH3OH.
a) The presence or absence of a catalyst makes no difference on the equilibrium position of the system hence the methanol remains constant.
b) The amount of methanol decreases because the equilibrium position shifts towards the left and more reactants are formed since the reaction is exothermic.
c) If the volume is decreased, there will be more methanol in the system because the equilibrium position will shift towards the right hand side.
d) Addition of helium gas has no effect on the equilibrium position since it does not participate in the reaction system.
e) if more CO is added the amount of methanol increases since the equilibrium position will shift towards the right hand side.
