If 1 kilowatt-hour (kWh) = 3.60 × 10^6 J, which of the following conversion factors should be used to convert 56.7 kWh to J?

An oxygen atom has a mass of and a glass of water has a mass of . Use this information to answer the question below. Be sure you

MariettaO [177]

Answer:

Number of moles of oxygen atoms having equal mass as glass of water = 3.12 moles

Note: The given question is missing some figures. Here is a complete similar question below.

An oxygen atom has a mass of 2.66*10^-23 g and a glass of water has a mass of 0.050 kg. What is the mass of 1 mole of oxygen atoms? Round your answer to 3 significant digits. How many moles of oxygen atoms have a mass equal to the mass of a glass of water? Round your answer to 2 significant digits.

Explanation:

A mole of a substance contains the Avogadro number of particles = 6.02 * 10²³

Therefore a mole of oxygen atoms contains 6.02*10²³ atoms.

mass of 1 atom of oxygen = 2.66*10⁻²³ g

Mass of 1 mole of oxygen atoms = mass of 1 atom * number of atoms in 1 mole

Mass of 1 mole of oxygen atoms = 2.66*10⁻²³ g * 6.02*10²³ = 16. 01 g

Mass of a glass of water = 0.050 Kg or 50 g

To determine the number of moles of oxygen atoms that have a mass equal to a glass of water i.e. 50 g, the formula below is used;

number of moles = mass/molar mass

mass of oxygen atoms= 50 g, molar mass or mass of one mole of oxygen atoms = 16.01 g

Therefore, number of moles of oxygen atoms = 50 g / 16.01 g = 3.12 moles

4 0

2 years ago

Which equation shows the proper setup to find the volume of a 0.250 M CaCl2 solution that contains 39.5 g of CaCl2?

Jlenok [28]

Molarity = number of mole of substance(n) / volume of solution (V).

n(CaCl2) = mass (CaCl2)/M(CaCl2)

M(CaCl2) = 40+2*35.5 = 111 g/mol

n(CaCl2) =39.5 g CaCl2*1 mol/111g

0.250 M = 39.5 g CaCl2*1 mol/111g*volume of solution (V).

volume of solution (V) = 39.5 g CaCl2*1 mol/(0.250 M*111g) = 1.42 L

4 0

2 years ago

Read 2 more answers

The average density of a carbon-fiber-epoxy composite is 1.615 g/cm3. the density of the epoxy resin is 1.21 g/cm3 and that of t

ra1l [238]

The composite material is composed of carbon fiber and epoxy resins. Now, density is an intensive unit. So, to approach this problem, let's assume there is 1 gram of composite material. Thus, mass carbon + mass epoxy = 1 g.

Volume of composite material = 1 g / 1.615 g/cm³ = 0.619 cm³
Volume of carbon fibers = x g / 1.74 g/cm³
Volume of epoxy resin = (1 - x) g / 1.21 g/cm³

a.) V of composite = V of carbon fibers + V of epoxy resin
0.619 = x/1.74 + (1-x)/1.21
Solve for x,
x = 0.824 g carbon fibers
1-x = 0.176 g epoxy resins

Vol % of carbon fibers = [(0.824/1.74) ÷ 0.619]*100 = 76.5%

b.) Weight % of epoxy = 0.176 g epoxy/1 g composite * 100 = 17.6%
Weight % of carbon fibers = 0.824 g carbon/1 g composite * 100 = 82.4%

4 0

2 years ago

What element is used in bright flashing advertising signs

Sergeu [11.5K]

The element used in advertising signs is neon.

4 0

2 years ago

Consider a culture medium on which only gram-positive organisms such as Staphylococcus aureus colonies can grow due to an elevat

Olin [163]

<h2>Selective & Differential Medium</h2>

Explanation:

Selective media allow specific types of organisms to develop, and inhibit the development of different living beings. The selectivity is cultivated in a few ways.For model, living beings that can use a given sugar are handily screened by making that sugar the main carbon source in the medium. On the other hand,selective hindrance of certain sorts of microorganisms can be accomplished by adding dyes, anti-infection agents, salts or explicit inhibitors which influence the digestion or enzyme systems of the living beings
Differential media are utilized to separate firmly related life forms or groups of living beings. owing to the pre of specific colors or synthetic compounds in the media, the creatures will deliver trademark changes or development designs that are utilized for ID or separation. An assortment of particular and differential media are utilized in clinical, demonstrative and water contamination research facilities, and in food and dairy laboratories
Selective media because elevated NaCI level is designed to help grow selective bacteria.differential media because the fermented sugar gives off a yellow halo which allows for differentiate between bacteria

4 0

2 years ago