If the plot of the reactant concentration versus time is nonlinear, but the concentration drops by 50% every 10 seconds, then the order of the reaction is ( )
A. zero order
B. first order
C. second order
D. third order
查看答案
If the plot of the reactant concentration versus time is linear, then the order of the reaction is ( )
A. zero order
B. first order
C. second order
D. third order
Find the pH of 0.175 M NaCN solution. For HCN, Ka = 4.9 × 10-10. ( )
A. 5.03
B. 11.28
C. 2.31
D. 8.97
For a process to occur spontaneously, ( )
A. the entropy of the system must increase
B. the entropy of the surroundings must increase
C. both the entropy of the system and the entropy of the surroundings must increase
D. the net change in entropy of the system and surroundings considered together must be a positive quantity
Which process results in the increase in entropy of the universe? ( )
A. the cooling of a hot cup of coffee in room temperature air
B. the evaporation of water from a desk at room temperature
C. the melting of snow above 0 °C
D. all of the above
微信支付 
支付宝支付