Consider a tank used in certain hydrodynamic experiments. after one experiment the tank contains 900 l of a dye solution with a concentration of 1 g/l. to prepare for the next experiment, the tank is to be rinsed with fresh water flowing in at a rate of 9 l/min, the well-stirred solution flowing out at the same rate. find the time that will elapse before the concentration of dye in the tank reaches 1% of its original value. (round your answer to one decimal place.)

Final answer:

The mass of 80.00 cm3 of platinum at 20 ℃, given its density of 21.45 g/cm3, is calculated to be 1716 grams (1.716 kilograms) using the formula Mass = Density × Volume.

Explanation:

To calculate the mass of 80.00 cm³ of platinum at a temperature of 20 ℃, given that the density of platinum is 21.45 g/cm³, we use the formula for density:

Density = Mass / Volume.

Rearranging this formula to find mass gives us Mass = Density × Volume.

Substituting the known values:

Gives us:

Mass = 21.45 g/cm3 × 80.00 cm³ = 1716 g or 1.716 kg.

Thus, the mass of 80.00 cm³ of platinum at 20 ℃ is 1716 grams or 1.716 kilograms.

Water molecules are dipolar because the more electronegative oxygen atom attracts electrons away from the hydrogen atoms, creating a charge imbalance within the molecule. The bent shape of water molecules prevents the cancellation of these local dipoles, resulting in a net dipolarity that enables water to engage in hydrogen bonding and dissolve ionic compounds.

Water molecules are dipolar due to the unique arrangement and electrical properties of their constituent atoms. The molecule of water consists of one oxygen atom and two hydrogen atoms. Oxygen, being more electronegative, draws the shared electrons from the hydrogen atoms towards itself more strongly.

This electron shift results in a partial negative charge on the oxygen atom and a partial positive charge on the hydrogen atoms, creating a polarity in the molecule. Additionally, due to water's bent shape, with an H-O-H angle of approximately 104.45°, these individual bond polarities do not cancel out as they might in a symmetrical molecule. Instead, they reinforce each other, leading to a significant molecular dipole where the molecule has an uneven distribution of charge—oxygen being anionic and hydrogen being cationic.

This dipolarity allows water to form hydrogen bonds with other water molecules or interact with ions, facilitating the dissolution of ionic compounds in water. In essence, the conditions that make water dipolar are its asymmetry and the varying electronegativity of oxygen and hydrogen atoms.

A neutral atom with 4 protons contains 4 electrons because, in a neutral atom, the number of protons and electrons are equal.

In chemistry, a neutral atom is one where the number of protons and electrons are equal. Protons carry a positive charge while electrons carry a negative charge. When these charges balance out, the atom is neutral. Hence, in the case of this atom with 4 protons, it must also have 4 electrons to keep it neutral. it means that it had no overall change So, the answer is that a neutral atom with 4 protons contains 4 electrons.

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The molar mass of CH4 is 16.0 g/mol.  

48.2 g CH4 x (1 mol / 16.0 g) = 3.01 mol CH4  

1 mol = 6.02 x 10^23 molecules  

3.01 mol CH4 x (6.02 x 10^23 molecules / 1 mol ) = 1.81 x 10^24 molecules

The lone pair electrons in a caffeine molecule are located in an sp³ hybrid orbital. This classification comes from observing atoms with similar structures, such as the nitrogen atom in ammonia. Hybrid orbitals are a theoretical model to explain electron behavior, and sp³ and sp² hybridizations are common in structures with lone pair electrons.

The lone pair electrons in a caffeine molecule are typically found in an sp³ hybrid orbital. For instance, in the nitrogen atom of ammonia, which is structurally similar to parts of caffeine, we find three bonding pairs and a lone pair of electrons surrounding the atom. These are directed to the four corners of a tetrahedron, evincing that the nitrogen atom is sp³ hybridized, with one hybrid orbital occupied by the lone pair.

Essentially, any central atom surrounded by three regions of electron density will exhibit sp² hybridization. This includes molecules with a lone pair on the central atom and molecules with two single bonds and a double bond connected to the central atom.

It's important to realize that these hybrid orbitals are a theoretical model to describe the behavior of electrons within a molecule. So, in caffeine, we can predict where lone pairs of electrons are likely to be based on our knowledge of electron behavior and atomic structure.

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The nucleus of a sulfur atom wil have 16 Neutron and two Hydrogen atoms can form covalent bond with sulfur.

A covalent bond is an electron exchange that causes the production of electron pairs between atoms.

Covalent bonding is a stable equilibrium of the attractive and repulsive forces between two atoms that occurs when they share electrons. Bonding pairs or sharing pairs are other names for these electron pairs.

Sulfur and hydrogen combine to form H₂S as a result (Hydrogen Sulphide).

H₂S is a moderately polar molecule due to its bent geometrical structure and the little difference in electronegativity between sulfur (2.58) and hydrogen (2.2), which results in a non-zero dipole moment.

Therefore, The nucleus of a sulfur atom wil have 16 Neutron and two Hydrogen atoms can form covalent bond with sulfur.

Learn more about Bonding here ;

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