Learning Catalytics Questions Chem

Consider a sample of gas with billions upon "uncountable" billions of molecules or atoms... What sorts of variables will determine or contribute to the measured "gas pressure" within this sample?

"all of the above are factors and some are interconnected"

Which wavelength of electromagnetic energy has the greatest energy? Speed of light = 3.00 x 108 m/s 10 nm 10 mm 1 nm 1 mm 1 m 10 m

1 nm

When a pure sample of a substance has relatively few interparticle forces, it tends to...

1. Be a gas 2. boil at a relatively low temp 3.melt at a relatively low temp 4.have a relatively low viscosity 5.boil at a relatively low surface tension 6.have a relatively high vapor pressure 7.have a relatively low deltaHvap

A very brief pulse of green laser light (λ=532 nm) lasting 371μs travels efficiently down a fiber optic cable. If this pulse delivered a total of 4.15x10-16 Joules, how many photons were contained within this pulse?

1110

Let's imagine that a single fiber unit in this carbon nanofiber has the formula C1000 (One thousand carbon atoms connected into a fiber unit.)! What would be the mass, in kilograms, of one mole (6.022x1023) of these nanofiber units?

12.01

What would be the mass in kilograms of a column of air of dimensions 1.00 m2 by 12.0 km? {We must make several (poor) assumptions here, most importantly that the air is a uniform 1.275 grams per liter throughout the column!}

15300

A sealed sample of gas at a constant temperature generates a Pressure-volume relationship described by the following graph... for this same sample of gas at the same temperature, what would be the volume (in milliliters, mL) when the applied pressure is 853.2 torr? (the graph has a slope of 25.7 atm*mL)

22.9

Copper sulfate is used in many pools and spas as a disinfectant. Ironically, this is the same CuSO4 is also considered an environmental pollutant. The copper ion and sulfate ions will often enter into a "complex" with water molecules as shown to the right. How many moles of oxygen atoms would be present in 1.2044 x 10 24 of these complexed units?

24

A 1.0 gram sample of solid iodine is places in a tube and the tube is sealed after all of the air has been removed. The tube and the solid iodine together weigh 27.0 grams. The tube is then heated until all of the solid iodine sublimes into gas. Will the weight after heating be

27 g

Determine the unknown volume to the correct number of significant figures. [The container is sealed and the pressure is constant]

3.88 one of them is 3.74 and 27.5 c and the other is ? L and 38.9 C

Write and balance a molecular equation illustrating aqueous mercury (I) nitrate reacting with aqueous hydrochloric acid to give aqueous mercury (II) chloride, water and nitrogen dioxide gas. What is the sum total of all coefficients used to balance this equation?

6 HgNO3(aq) + 2HCl(aq) ➩ HgCl2(aq) + H2O(l) + NO2(g)

These three pressure-volume curves were obtained with the same gas sample at different contestant temperatures... Which curve represents the gas at the lowest temperature?

A (the lowest one)

Consider samples of five pure metals, each sample having a mass of one hundred grams (100. g). Which sample contains the greatest number of moles of atoms? Al Fe Cu Zn Ag they all contain the same number of moles.

Al Since all samples have the same mass, one with the lightest atomic mass has the largest number of atoms.

Elements in the same A react chemically similarly because they have the same number of B

Group, Valence electrons

When __ react, one or two electrons are "shared", but not "50/50". These atoms "share" electrons "unevenly" to form a __ bond

Hydrogen & oxygen polar covalent

On a clear day in Utah, the sky is a beautiful blue color. This is because every morning sky fairies who live 60,000 feet above the surface of the earth paint the sky blue. The second sentence is an example of a(n)...

Hypothesis

When intense, bright red light strikes a sample of cesium (Cs) metal in a photoelectric effect experiment, no electrons are ejected from the surface. In contrast, a dim (faint) blue light illuminates the Cs metal surface and electrons are ejected and their K.E. is measured. A plot of the kinetic energy of the ejected electrons versus incident photon frequency looks like

Its completely flat at the beginning and then goes up

On a clear day in Utah, the sky is a beautiful blue color. This is because every morning sky fairies who live 60,000 feet above the surface of the earth paint the sky blue. The first sentence is an example of a(n)...

Observation

When intense, bright red light strikes a sample of cesium (Cs) metal in a photoelectric effect experiment, no electrons are ejected from the surface. In contrast, a dim (faint) blue light illuminates the Cs metal surface and electrons are ejected and their K.E. is measured. Based on these observations, what can be concluded?

Red photons have less energy than blue photons.

Interestingly, elements that have high electronegativities also tend to be relatively..

Small, nonmetallic, and have high IP energy

Which of the following molecules is non-polar overall? SF4 CHCl3 F2O XeF4 ClF3

XeF4

On a clear day in Utah, the sky is a beautiful blue color. This is because every morning sky fairies who live 60,000 feet above the surface of the earth paint the sky blue. Using a scientific method, what would be the next logical step toward explaining why the sky is blue?

develop a new hypothesis perform an experiment modify the present hypothesis

Covalent bonds form from the tendency of a system to seek...

its lowest possible energy state

A 1.0-gram sample of solid iodine is placed in a tube and the tube is sealed after all of the air has been removed. The tube and the solid iodine together weigh 27.0 grams. The tube is then heated until all of the solid iodine sublimes into a gas. Will the weight after heating be...(your answer from previous question) This is because...

mass is conserved

Molecules are typically formed when two or more come together and valence electrons salts are usually formed when a mental atom and a valence electron with/to a atom; the resulting +/- ions attract, forming a regular crystalline lattice

nonmetals, share, transfer, nonmetals

Describe the electron configurations for the chemical species in the isoelectronic series; N3- O2- F- Ne Na+ Mg2+ Al3+ Most of these chemical species are likely to be...

not chemically reactive at all Because they all have the inert gas electron configuration

When __ react, electrostatically-charged ions form. These ions quickly attract each other to form a __ bond

sodium & chlorine ionic