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4 days ago

A student needed exactly 45.3ml of a solution. what piece of glassware should that student use? justify your choice.

1 answer:

7 0

The student should use a graduated cylinder. This type of equipment is the standard in laboratories for measuring liquid volumes. It features measurements marked at intervals of 1, 0.5, or 0.1, depending on the maximum capacity. However, it is essential to observe the bottom of the meniscus level with your eyes to get an accurate reading.

You might be interested in

Why are salt and sugar both able to dissolve in water, even though the solutes have different types of chemical bonding?

castortr0y [923]

Response: Water is a polar substance, facilitating the dissolution of ionic compounds due to the principle that similar types mix.

Ionic interactions occur between salt and water

Sugar contains hydroxyl groups that can form hydrogen bonds with water molecules.

[Hydrogen bond: this refers to the attraction between a hydrogen atom bonded to a highly electronegative atom (like F, O, or N) and another highly electronegative atom (F, O, or N)]

Thus, due to the presence of hydrogen bonds, sugar dissolves in water.

Clarification: Water molecules are polar, exhibiting partial positive charges on the hydrogen atoms and a partial negative charge on the oxygen atom. This allows them to interact with ionic compounds such as salt (NaCl). These interactions occur through the partial charges on water, which attract opposite charges. When dissolved in water, NaCl dissociates into sodium and chloride ions; sodium ions are surrounded by negatively charged oxygen from water, while chloride ions are surrounded by positively charged hydrogens from water. As a result, salt dissolves in water.

Sugar, being a covalent compound, has bonds where electrons are shared unevenly, creating slight positive and negative charges. This characteristic allows sugar to interact with the polar ends of water, facilitating its dissolution. Therefore, it can be stated that sugar dissolves in water due to both substances being polar.

In summary, water is capable of dissolving most polar or ionic substances, as seen with sugar and salt.

6 0

8 days ago

Read 2 more answers

1. For which of these elements would the first ionization energy of the atom be higher than that of the diatomic molecule?

alisha [964]

Answer: The correct selection is (b).

Explanation:

The energy required to detach an electron from an atom or ion in its gaseous state is termed ionization energy.

This indicates that a smaller atom necessitates a greater amount of energy to remove its valence electron. The reason for this is that there exists a strong attraction between the nucleus and the electrons in smaller atoms or elements.

Therefore, a significant amount of energy is needed to dislodge the valence electrons.

The electronic configuration for helium is $1s^{2}$ . Hence, due to its fully occupied valence shell, it exhibits greater stability.

Consequently, a large amount of energy is needed to remove an electron from a helium atom.

In conclusion, from the choices provided, the ionization energy of helium will be greater than that of the diatomic molecule.

7 0

9 days ago

The speed of light in a vacuum is 2.998 × 10 8 8 m/s. How long does it take for light to circumnavigate the Earth, which has a c

castortr0y [923]

Answer:- 0.134 seconds

Solution:- The speed is given as $2.988*10^8\frac{m}{s}$ and the circumference is 24900 miles which is same as the distance light have to covered. It asks to calculate the time required to cover this distance by the light.

Unit conversion is needed from miles to meters since the speed is given in meters per second.

1 mile = 1609.34 meters

Thus, $24900mile(\frac{1609.34meter}{mile})$

= 40072566 meters

Now, $speed=\frac{distance}{time}$

Rearranged for time, that gives: $time=\frac{distance}{speed}$

Inserting the values:

$time=\frac{40072566meter}{2.988*10^8\frac{meter}{second}}$

= 0.134 seconds

Hence, light would take 0.134 seconds to traverse the indicated distance. The answer without the unit is 0.134.

8 0

4 days ago

Equimolar samples of CH3OH(l) and C2H5OH(l) are placed in separate, previously evacuated, rigid 2.0 L vessels. Each vessel is at

Alekssandra [968]

Answer:

Complete Question:

Equimolar quantities of CH3OH(l) and C2H5OH(l) are placed in separate 2.0 L containers that have been evacuated beforehand. Pressure gauges are attached to each container, and the temperature is maintained at 300 K. In both containers, liquid is consistently visible at the bottom. The varying pressure within the vessel that contains CH3OH(l) is illustrated below.

In comparison to the equilibrium vapor pressure of CH3OH(l) at 300 K, the equilibrium vapor pressure of C2H5OH(l) at 300 K is

ANSWER : lower, since the London dispersion forces among C2H5OH molecules surpass those among CH3OH molecules.

Explanation:

To clarify the answer provided, let’s begin by defining some concepts.

The London dispersion force is the least strong type of intermolecular force. It is a temporary force that arises when the electron arrangement in two neighboring atoms creates transient dipoles.

The vapor pressure of a liquid reflects the equilibrium pressure of its vapor above the liquid (or solid); specifically, it represents the pressure associated with the evaporation of a liquid (or solid) in a sealed environment above the substance.

The pressure will be lower due to the stronger London dispersion forces acting between C2H5OH molecules compared to those between CH3OH molecules. This implies that when intermolecular forces are stronger, they intensify the interactions binding the substance together, thereby reducing the liquid's vapor pressure at any given temperature and making it more difficult to vaporize the substance.

Note: The London dispersion force for C2H5OH is more substantial than for CH3OH because C2H5OH has more electrons than CH3OH.

3 0

15 days ago

The concentration of Si in an Fe-Si alloy is 0.25 wt%. What is the concentration in kilograms of Si per cubic meter of alloy?

KiRa [971]

Answer: The mass of Si in kilograms is, $19.55kg/m^3$

Explanation:

Given that the Si concentration in an Fe-Si alloy is 0.25 weight percent, this translates to:

Mass of Si = 0.25 g = 0.00025 kg

Mass of Fe = 100 - 0.25 = 99.75 g = 0.09975 kg

Density of Si = $2.32g/cm^3=2.32\times 10^6g/m^3$

Density of Fe = $7.87g/cm^3=7.87\times 10^6g/m^3$

Next, we need to find the quantity of Si in kilograms per cubic meter of alloy.

Si concentration in kilograms = $\frac{\text{Weight of Si in 100 g of alloy}}{\text{Volume of 100 g of alloy}}$

Si concentration in kilograms = $\frac{\text{Weight of Si in 100 g of alloy}}{\frac{\text{Wight of Fe}}{\text{Density of Fe}}+\frac{\text{Wight of Si}}{\text{Density of Si}}}$

By substituting all the provided values into this formula, we arrive at:

Si concentration in kilograms = $\frac{0.00025kg}{\frac{99.75g}{7.87\times 10^6g/m^3}+\frac{0.25g}{2.23\times 10^6g/m^3}}$

Si concentration in kilograms = $19.55kg/m^3$

Hence, the mass of Si in kilograms is, $19.55kg/m^3$

5 0

8 days ago