Answer:
Physical changes only change the appearance of a substance, not its chemical composition. Chemical changes cause a substance to change into an entirely substance with a new chemical formula. Chemical changes are also known as chemical reactions.
Explanation:
The energy possessed by chemicals is known as chemical energy.
The correct answer is 12.044 × 10²³ molecules.
The molecular mass of H₂S is 34 gram per mole.
Number of moles is determined by using the formula,
Number of moles = mass/molecular mass
Given mass is 68 grams, so no of moles will be,
68/34 = 2 moles
1 mole comprises 6.022 × 10²³ molecules, therefore, 2 moles will comprise = 6.022 × 10²³ × 2
= 12.044 × 10²³ molecules.
P1V1 = P2V2
P1 = 6.20 atm
V1 -?
P2= <span>9.150 atm
V2 = 322 mL
</span>6.20 atm*V1 = 9.150 atm *322 mL
V1=9.150 atm *322 mL/6.20 atm ≈ 475 mL
V1 = 475 mL
I think the correct answer from the choices listed above is the third option. <span>In the redox reaction given, the element that was reduced was Fe or iron. It's charge reduced from +3 to zero, a neutral charge. Hope this answers the question. Have a nice day.</span>