Question

calculator and the provided your answers on the provided akindi answer sheet. make sure recorded on your akindi sheet. turn in both your akindi sheet and your exam.
this is exam version b
1.00 atm = 760 mmhg = 760 torr = 101.325 kpa = 29.92 inhg = 14.7 psi = 1.013 bar
r = 0.08206 l·atm/mol·k = 8.314 m³·pa/mol·k = 62.36 l·torr/mol·k = 8.314 j/mol·k
c = 3.00 × 10⁸ m/s h = 6.62 × 10⁻³⁴ j/hz

1. what is the wavelength of light that has a frequency of 1200 khz?

a) 1200 m b) 2.5 × 10² m c) 250 m d) 2.5 × 10⁸ m

1. what is the frequency of light that has a wavelength of 2.50 cm?

a) 1.20 × 10⁸ hz b) 1.20 × 10¹⁰ hz c) 7.50 × 10⁸ hz d) 2.50 × 10⁷ hz

1. naphthalene, c₁₀h₈, combusts according to the equation:

c₁₀h₈ + 12 o₂ → 10 co₂ + 4 h₂o δh = -5771 kj/mol
how much heat is released if 25.00 g of naphthalene are combusted?
a) 1126 kj b) 5771 kj c) 2841 kj d) 1947 kj

1. a process has a negative value for δh. the process is ______.

a) endothermic b) exothermic c) spontaneous d) electrolytic

1. going left to right across a period of the periodic table, electron affinity ______.

a) becomes more positive b) becomes more negative
c) remains constant d) is unpredictable
questions 6 - 9 refer to the following scenario:
a 0.6587 g sample of benzoic acid is combusted in a bomb calorimeter, causing a temperature increa
4.87 °c. then, 0.5748 g of an unknown solute are combusted, and the temperature increases by 5.1
benzoic acid has a heat of combustion of 26.38 kj/g.
how much heat was released in the combustion of the benzoic acid?
a) 26.36 kj b) 17.38 kj c) 15.16 kj d) 40.02 kj
what is the heat capacity of the calorimeter, in kj/°c?
a) 568 b) 5.417 c) 1.874 d) 9.748
how much heat was released by the combustion of the unknown?
a) kj b) 1.74 kj c) 18.30 kj d) 28.95
what is the heat of combustion of the unknown, in kj/g?
a) b) 39.47 c) 18.42 d) 3

Explanation:

Step1: Recall the formula for wavelength

The formula relating the speed of light (\(c\)), frequency (\(f\)), and wavelength (\(\lambda\)) is \(c = \lambda f\), so \(\lambda=\frac{c}{f}\).

Step2: Substitute the values

Given \(c = 3.00\times10^{8}\space m/s\) and \(f = 1200\space kHz=1200\times10^{3}\space Hz = 1.2\times10^{6}\space Hz\).
Substitute into the formula: \(\lambda=\frac{3.00\times10^{8}\space m/s}{1.2\times10^{6}\space Hz}\)

Step3: Calculate the wavelength

\(\frac{3.00\times10^{8}}{1.2\times10^{6}}=\frac{3.00}{1.2}\times10^{8 - 6}=2.5\times10^{2}\space m = 250\space m\)

Answer:

C) 250 m