which of the following quantities is path-dependent?
which of the following quantities is intensive property?
which of the following statements about internal energy is wrong?
the rate coefficient of a certain reaction was 0.231 , and the initial concentration of reactants was 0.5, so the half-life of the reaction was
the addition of a catalyst can change which of the following physical quantities of a chemical reaction:
there is a chemical reaction which has only one reactant. its rate coefficient k=0.05.the initial concentration of the reactant is 0.4 . when the reaction rate drops to 1/4 of the initial rate, the required time is:
there is a consecutive reaction where all the elementary steps are in the same reaction order. the reaction is carried out under constant volume condition. if we want to obtain the maximum yield of the intermediate, we shall:
for a reaction a→b, if the concentration of reactant a is reduced by half, its half-life is also reduced by half, then the reaction order of this reaction is:
the relation between the rate coefficient k of a reaction and the rate coefficients of each elementary reactions is , then the relation between the apparent activation energy e of the reaction and the activation energy , , and of each elementary reaction is:
for a first-order gas-phase parallel reaction: a → b, a → c, where the pre-exponential factor, activation energy , and all of them are independent of temperature. it is now measured that is 100 at 298 k, and the value of at 754 k is
for secondary reactions, the lower the initial concentration, the shorter the time required when the reactants convert the same percentage.
according to the activated complex theory, the saddle point on the potential energy surface is the highest point of energy.
if the rate of a reaction is first order kinetic, it must be a monomolecular reaction.
the standard enthalpy of combustion of c5h12 (g) is -3520 kj/mol, the standard enthalpies of formation of co2 (g) and h2o (l) are -395 kj/mol and -286 kj/mol, respectively. caculate the standard enthalpy of formation of c5h12 (g):
the constraint for the equation qv=du is
which of the following quantities is zero?
a heat engine operates between two temperatures 400 °cand 50 °c, calculate the maximum efficiency of this heat engine?
this equation is true for ideal gas.
cp-cv=nr. this equation is valid for any gas.
which of the following processes (under constant t and p) displays a negative ds?
which of the following statements about entropy is wrong?
for pure ideal gas, which of the following is positive?
the chemical potential of 1 mol of ideal gas at 300 k and 100 kpa is μ1，while that is μ2 at 300 k and 80 kpa. then μ1______μ2
the chemical potential of substance b can be defined as
when benzene and toluene at 300 k and 101.325 kpa are mixed to form an ideal solution, there is a change in
the partial molar helmholtz energy is defined as
the height at which the liquid rises in the capillary is inversely proportional to:
under certain pressure and temperature, ( ) will affect the material's surface gibbs function δg.
in comparison with ordinary crystals, the following properties are described incorrectly:
porous silicon has strong water absorption performance. after absorbing water, the silicone surface gibbs free energy δg will ( ).
inject a little mercury (hg) into a horizontal glass capillary tube. the two ends of the horizontal mercury column are convex. if heating the right convex of mercury, the mercury in the capillary will move ( ).
the greater the intermolecular force is, the greater the surface tension is.
the surface tension of solution always decreases with the increase of solution concentration.
the tyndall phenomenon can be used to distinguish sols from all molecule dispersion systems.
in the external dc electric field, agi positive sol moves towards the negative electrode, while its diffusion layer moves towards the positive electrode.
nahco3（s）in a vacuum vessel decomposed partially to na2co3(s), h2o(g) and co2(g), when it reached the following equilibrium :2nahco3(s) =na2co3(s) h2o(g) co2(g), which one is true?
both t and p have definite values at the triple point for a pure substance.
光子的静止质量是（ ）
单电子原子的一个激发态ψ3,1,1(r,θ,φ)，其磁量子数m =
描述微观粒子的波函数ψ，其含义是表示微观粒子在空间某体积微元内出现的概率。
同一能级的不同状态的数目叫能级简并度。
多电子原子系统的能量仅由主量子数决定。
for which of the following sets of values of △h and △s will a reaction be spontaneous only at high temperature?
for chemical reaction aa(g) ＋bb (g) ＝yy (g) ＋zz (g), σνb > 0. when increase the reaction pressure (p↑) , then the equilibrium will