In which case is the work done on the system always positive?

When you look out the window at the blue sky you see light of a wavelenth of  473 nm. A photon of that light has a frequency of [a]Hz and an energy of [b] J. Must show your work (scratch paper) to receive credit.  

Light can be made to have a higher intensity by raising its

Write the full electron configuration for S: (Do not consider exceptions. Make sure to follow the order following the Aufbau principle, use the following format without superscripts: 1s2 2s2 2p6…)

When a 1.397 g sample of thymol, C10H14O(s) (a preservative), is burned in a bomb calorimeter. The temperature increase from 20.00 °C to 31.23 °C, and the heat capacity of the bomb calorimeter is 4.68 kJ/°C. What is the heat of combustion of thymol, expressed in kilojoules per mole of C10H14O?

Write the condensed (short form) electron configuration for Fr:( Make sure to follow the order following the Aufbau principle. Do not consider exceptions. Do not use superscripts, do not write the brackets on the noble gas. Use the following format Ne – 3s2 ….)

A 91.9 MHz radio transmitter has a wavelength of [a] m and an energy of [b] J. Must show your work (scratch paper) to receive credit.  

Given the data:  N2H4(l) + O2 (g) → N2(g) + 2 H2O (l) ΔH° = – 622.2 kJ 2 H2(g) + O2 (g) → 2H2O (l) ΔH° = -571.6 kJ H2(g) + O2 (g) → H2O2(l) ΔH° = – 187.8 kJ   using Hess’s Law the ∆H for the reaction below is [a] kJ:N2H4 (l) + 2 H2O2 (l) → N2(g) + 4 H2O (l)Must show your work (scratch paper) to receive credit.

Given the following equations and ∆H° values:                                                               OF2(g) + H2O(l) → O2(g) + 2 HF(g) ∆H° = -276.6 kJ SF4(g) + 2 H2O(l) → 4 HF(g) + SO2(g) ∆H° = -827.5 kJ S(s) + O2(g) → SO2(g) ∆H° = -296.9 kJ  determine the heat of reaction (kJ) at 298 K for the reaction:  2 OF2(g) + 2 S(s) →SO2(g) + SF4(g) Must show your work (scratch paper) to receive credit.

Write the full electron configuration for Ti: (Do not consider exceptions. Make sure to follow the order following the Aufbau principle, use the following format without superscripts: 1s2 2s2 2p6…)