Answer:
14.32g
Explanation:
Initial temperature = 83.8°C
Final temperature = 77.1°C
Temperature change, ΔT = 83.8°C - 77.1°C = 6.7
Heat, H = 167J
Specific heat, c = 1.740J/g °C
m = ?
All these parameters are related with the equation below;
H = mcΔT
m = H / cΔT
m = 167 / (1.740 * 6.7)
m = 167 / 11.658 = 14.32g
One important drawback of the use of hcfcs as a replacement for cfcs is that hcfcs are more potent greenhouse gases.
<h3>
What is hcfcs?</h3>
HCFCs is an acronym for hydrochlorofluorocarbons (HCFCs).
Thye are fully or partly halogenated hydrocarbons that contain carbon (C), hydrogen (H), chlorine (Cl), derived from alkane family.
<h3>What is cfcs?</h3>
CFCs is an acronym for Chlorofluorocarbons (CFCs), derived from alkane family like hydrochlorofluorocarbons.
<h3>Disadvantage of hcfcs over cfcs</h3>
One important drawback of the use of hcfcs as a replacement for cfcs is that hcfcs are more potent greenhouse gases.
Learn more about hcfcs and cfcs here: brainly.com/question/15885478
<h2>Entropy of the system decreases when methane gas and oxygen gas combust to form carbon dioxide and water.</h2>
Explanation:
- Salt crystals when dissolved in water the bond between the molecules of crystals are broken down increasing the movement between the atoms hence entropy is increased.
- When air escapes from a hole in the balloon,the entropy increases as the air present inside the balloon occupies small volume as compared to outside.
- Ice when melts at room temperature its entropy increases because the molecule in the ice are closely packed hence less movement between the molecules.
- When water boils the kinetic energy increases or themovement between the atoms increases which increases the entropy.
Hence, the option (a), (b), (c), and (d) are not suitable to the statement that "the entropy of the system decreases".
- During combustion of methane gas there is release of carbon dioxide gas and water .Here, entropy decreases due to the formation of water which is due to overall decrease in the kinetic energy of the system.
Diabeties
Can run in the family, from ancestors
a) According to the reaction equation:
CaSO4(s) ↔ Ca2+(aq) + SO4-(aq)
when Kc = [Ca2+][SO4-]
when [Ca2+] = [SO4-] = X
and we have Kc = 2.4 x 10^-5 so ,by substitution we can get [Ca2+]&[SO4-]
2.4 x 10^-5 = X^2
∴X = 0.0049
∴[SO4-] = [Ca2+] = 0.0049 M
b) when we have [Ca2+] = 0.0049 M so we can get the no.of moles of CaSO4:
moles of CaSO4 = molarity * volume
= 0.0049 M * 1.2 L
= 0.00588 moles
when we know the molar mass of CaSO4 = 136.14 g/ mol, So we can get the mass:
∴mass of CaSO4 = moles of CaSO4 * molar mass of CaSO4
= 0.00588 moles * 136.14 g/mol
= 0.8 g
