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bridgetcentral270
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1)When potassium cyanide (KCN) reacts with acids, a deadly poisonous gas, hydrogen cyanide (HCN), is given off. Here is the equation below.
KCN(aq) + HCl(aq) KCl(aq) + HCN(g)
If a sample of 0.200 g of KCN is treated with an excess of HCl, calculate the amount of HCN formed, in grams.
2)Consider the combustion of carbon monoxide (CO) in oxygen gas.
2 CO(g) + O2(g) 2 CO2(g)
Starting with 4.40 moles of CO, calculate the number of moles of CO2 produced if there is enough oxygen gas to react with all of the CO.
3)Hydrogen fluoride is used in the manufacture of Freons (which destroy ozone in the stratosphere) and in the production of aluminum metal. It is prepared by the reaction below.
CaF2 + H2SO4 CaSO4 + 2 HF
In one process 6.00 kg of CaF2 are treated with an excess of H2SO4 and yield 1.26 kg of HF. Calculate the percent yield of HF.
4) (a) Calculate the frequency (in Hz) of an electromagnetic wave with a wavelength of 454 m. (b) Calculate the frequency (in Hz) of an electromagnetic wave with a wavelength of 605 nm. (c) Calculate the wavelength (in nm) of an electromagnetic wave with a frequency of 5.0 x 10^17 Hz.
5) The carat is the unit of mass used by jewelers. One carat is exactly 200 mg. How many carbon atoms are present in a 39 carat diamond?
6) E4 -1.0 x 10^-19 J
E3 -5.0 x 10^-19 J
E2 -10 x 10^-19 J
E1 -15 x 10^-19 J
(a) What is the wavelength of the photon needed to excite an electron from E1 to E4?
(b) What is the energy (in joules) a photon must have in order to excite an electron from E2 to E3?
(c) When an electron drops from the E3 level to the E1 level, the atom is said to undergo emission. Calculate the wavelength of the photon emitted in this process.
any answers would be great
KCN(aq) + HCl(aq) KCl(aq) + HCN(g)
If a sample of 0.200 g of KCN is treated with an excess of HCl, calculate the amount of HCN formed, in grams.
2)Consider the combustion of carbon monoxide (CO) in oxygen gas.
2 CO(g) + O2(g) 2 CO2(g)
Starting with 4.40 moles of CO, calculate the number of moles of CO2 produced if there is enough oxygen gas to react with all of the CO.
3)Hydrogen fluoride is used in the manufacture of Freons (which destroy ozone in the stratosphere) and in the production of aluminum metal. It is prepared by the reaction below.
CaF2 + H2SO4 CaSO4 + 2 HF
In one process 6.00 kg of CaF2 are treated with an excess of H2SO4 and yield 1.26 kg of HF. Calculate the percent yield of HF.
4) (a) Calculate the frequency (in Hz) of an electromagnetic wave with a wavelength of 454 m. (b) Calculate the frequency (in Hz) of an electromagnetic wave with a wavelength of 605 nm. (c) Calculate the wavelength (in nm) of an electromagnetic wave with a frequency of 5.0 x 10^17 Hz.
5) The carat is the unit of mass used by jewelers. One carat is exactly 200 mg. How many carbon atoms are present in a 39 carat diamond?
6) E4 -1.0 x 10^-19 J
E3 -5.0 x 10^-19 J
E2 -10 x 10^-19 J
E1 -15 x 10^-19 J
(a) What is the wavelength of the photon needed to excite an electron from E1 to E4?
(b) What is the energy (in joules) a photon must have in order to excite an electron from E2 to E3?
(c) When an electron drops from the E3 level to the E1 level, the atom is said to undergo emission. Calculate the wavelength of the photon emitted in this process.
any answers would be great