Answer:
B is False
Explanation:
In physical chemistry we always look from system's perspective, so if we heat something ΔH is positive and if the system gives heat out then ΔH is negative.
A. We have to give energy to benzene to evaporate it. Statement true.
B. If heat is absorbed then the enthalpy must be positive.
C. The heat is absorbed then ΔH is positive.
D. Usually for burning heat is exposed from system. So enthalpy is negative.
E. Obvious
Answer:
d. One single bond and two double bonds.
Explanation:
The octate rule is a chemical rule in which the atoms prefer to have eight electrons in the valence shell. Where a single bond provide two electrons and a double bond provide 4 electrons. Thus:
a. Two double bonds
. Two double bonds provide 8 electrons. Octate rule <em>is not </em>violated
b. Three single bonds and one pair of electrons
. Three single bonds provide 6 electrons and one pair of electrons provide two electrons. Thus, you have eight electrons and octate rule <em>is not</em> violated
c. Two single bonds and one double bond
. Two single bonds provide four electrons and one double bond 4. Thus, you have eight electrons and octate rule <em>is not </em>violated.
d. One single bond and two double bonds. One single bond provides two electrons and two double bonds 8. Thus, you have 10 electrons and <em>octate rule is violated.</em>
e. Four single bonds. Four single bonds provide 8 electrons. Octate rule<em> is not </em>violated.
I hope it helps!
Answer:
Explanation: since oxalic acid is a weak acid it wont provide a strong acidic medium. So in order to provide a strong acidic medium dilute sulphuric acid is added.
<span>Heavier atoms make denser materials</span>
<h3><u>Answer;</u></h3>
Higher velocity of particles
<h3><u>Explanation;</u></h3>
The diffusion rate is determined by a variety of factors which includes;
- Temperature such that the higher the temperature, the more kinetic energy the particles will have, so they will move and mix more quickly and the diffusion rate will be high.
- Concentration gradient such that the greater the difference in concentration, the quicker the rate of diffusion.
- Higher velocity of particles increases the diffusion rate as this means more kinetic energy by the particles and hence the particles will mix and move faster, thus higher diffusion rate.
