Answer:
the entropy change for the surroundings when 1.68 moles of Fe2O3(s) react at standard conditions = 49.73 J/K.
Explanation:
3Fe2O3(s) + H2(g)-----------2Fe3O4(s) + H2O(g)
∆S°rxn = n x sum of ∆S° products - n x sum of ∆S° reactants
∆S°rxn = [2x∆S°Fe3O4(s) + ∆S°H2O(g)] - [3x∆S°Fe2O3(s) + ∆S°H2(g)]
∆S°rxn = [(2x146.44)+(188.72)] - [(3x87.40)+(130.59)] J/K
∆S°rxn = (481.6 - 392.79) J/K =88.81J/K.
For 3 moles of Fe2O3 react, ∆S° =88.81 J/K,
then for 1.68 moles Fe2O3 react, ∆S° = (1.68 mol x 88.81 J/K)/(3 mol) = 49.73 J/K the entropy change for the surroundings when 1.68 moles of Fe2O3(s) react at standard conditions.
Answer:
185.1 m/s
Explanation:
The average speed of an object is a scalar quantity telling us how fast is the object moving over a certain distance.
This quantity is calculated as
where
d is the distance covered by the object
t is the time elapsed
v is the average speed
In this problem we have:
d = 1500.0 m is the distance covered by Ken
t = 8.1018 s is the time taken
Substituting into the formula, we find the average speed:
Answer:
18.2784 g
Explanation:
First we <u>convert 180 lb to kg</u>:
- 180 lb * 0.453 kg / lb = 81.6 kg
Now we <u>calculate the mass of antibiotic taken in one day</u>:
- 8.0 mg/kg * 81.6 kg = 652.8 mg
Given that it is taken twice daily, <em>in one day the person would take (652.8 * 2) 1305.6 mg</em>. In grams that mass would be:
- 1305.6 mg / 1000 = 1.3056 g
Finally we multiply those 1.3056 daily grams by the 14 days in two weeks:
- (1.3056 g) * 14 = 18.2784 g
Answer:
False
Explanation:
Atomic bonding can be of two types:
Ionic bonds: The bond formed between two opposite charged ions. The strong electrostatic force acting between the ions make them compounds of high stability . Example: NaCl
Covalent bonds: The bond formed by sharing of the electrons between the atoms. The balance between the attractive force (nucleus, electron) and repulsive force (electron, electron or nucleus, nucleus) makes the compound stable. Example:
The bonds are either formed by transferring (losing and gaining) or sharing of electrons. Thus, compound forming these bonds share or transfer electrons to attain noble gas configuration. Thus, they lack free electrons.
There are 22 pairs of <span>homologous chromosomes are found in human body cells.</span>