What is an example of volume

Why is the formation of hydrogen bonds between water molecules categorized as cohesion

marishachu [46]

Answer: Because of the polarity of water molecules

Molecular <u>cohesion</u> is the attraction that molecules have for others of their same type. Depending on the intensity of this attraction, a substance is in a solid, liquid or gaseous state.

In this sense, water ( $H_{2}O$ ) can stick to itself through hydrogen bonds, because a water molecule consists of 2 hydrogen atoms attached to 1 oxygen atom.

The oxygen atom tends to monopolize more electrons and keeps them away from hydrogen. Then, it can be said that a water molecule will have a negative side (oxygen) and a positive side (hydrogen).

<u>Thanks to this polarity</u>, water molecules can stick together with the formation of<u> hydrogen bonds</u> to attract a partial positive charge of hydrogen and a more electronegative atom, such as oxygen.

6 0

4 years ago

A coffee-cup calorimeter is used to determine the heat of reaction for the reaction of compound A with compound B. A(aq) + B(aq)

Sergeeva-Olga [200]

Answer:

$\rm 1.64\times 10^{3}\; J$ .

Explanation:

Assume that his calorimeter is sufficiently effective, such that no heat had escaped to the surroundings. Heat from this solution would be absorbed by either

the solution, or
the coffee cup.

Temperature change: $33.637 - 23.722 = \rm 9.915\; ^\circ C$ .

<h3>Heat absorbed by the solution:</h3>

Only the specific heat capacity (per unit mass) of the solution is given. Both the mass of the solution and the temperature change will be required for determining the energy change. Start by finding the mass of the solution.

$m = \rho \cdot V = 2\times 16.10 \times 1.00 = \rm 32.10\; g$ .

Calculate the amount of heat absorbed from the specific heat:

$Q = c\cdot m \cdot \Delta T = 4.814\times 32.10 \times 9.915 = \rm 1335.80\; J$ .

<h3>Heat absorbed by the coffee cup:</h3>

The heat capacity of the coffee cup is given. Only the temperature change will be required for finding the amount of heat absorbed.

$Q = C\cdot \Delta T = \rm 30.7\times 9.915 = 304.391\; J$ .

<h3>Heat that this reaction produces</h3>

Find the sum of the two parts of heat. Round to three significant figures as in the heat capacity of the coffee cup and the density of the solution.

$\rm 1335.80+ 304.391 = 1.64\times 10^{3}\; J$ .

8 0

4 years ago

A police officer in hot pursuit of a criminal drives her car through an unbanked circular (horizontal) turn of radius 300 m at a

Mamont248 [21]

Answer:

The angle (relative to vertical) of the net force of the car seat on the officer to the nearest degree is <u>10°.</u>

Explanation:

Given:

Mass of the driver is, $m=55\ kg$

Radius of circular turn is, $R=300\ m$

Linear speed of the car is, $v=22.2\ m/s$

Since, the car makes a circular turn, the driver experiences a centripetal force radially inward towards the center of the circular turn. Also, the driver experiences a downward force due to her weight. Therefore, two forces act on the driver which are at right angles to each other.

The forces are:

1. Weight = $mg=55\times 9.8=539\ N$

2. Centripetal force, 'F', which is given as:

$F=\frac{mv^2}{R}\\F=\frac{55\times (22.2)^2}{300}\\\\F=\frac{55\times 492.84}{300}\\\\F=\frac{27106.2}{300}=90.354\ N$

Now, the angle of the net force acting on the driver with respect to the vertical is given by the tan ratio of the centripetal force (Horizontal force) and the weight (Vertical force) and is shown in the triangle below. Thus,

$\tan \theta=\frac{90.354}{539}\\\tan \theta=0.1676\\\theta=\tan^{-1}(0.1676)=9.52\approx 10$ °

Therefore, the angle (relative to vertical) of the net force of the car seat on the officer to the nearest degree is 10°.

3 0

3 years ago

1. Define speed

Tom [10]

Answer:

1. speed is the distance travelled by an object in unit time

2. velocity is the displacement of a body in in unit time

3. formula of speed =total distance (d)÷ total elapsed time

6 0

3 years ago

In atomic bombs, a relatively small amount of matter (uranium atoms) is converted to a relatively huge amount of energy (the bla

viva [34]

Explanation:

In atomic bombs, nuclear reactions is at work.

Depending on the reaction, matter is converted to energy either by nuclear fusion or fission process.

Nuclear reactions takes place in the nucleus of elements.
Inside the nucleus, the bulk of the mass of atoms are concentrated via by the presence of protons and neutrons.
These particles called nucleons typifies the mass of an atom.
When nuclear reactions occur, they take place in the nucleus of atoms.
This interaction leads to the conversion of some of these masses to energy.
As predicted by the Einstein's equation, E = mc², mass m and energy E are both equivalent.
c is the speed of light.
Instead of converting all the mass to product, some are transformed into energy.
The mass and energy equivalence typifies nuclear reactions.
There is always a mass deficit that accompanies such reactions.

learn more:

Nuclear reactions brainly.com/question/10094982

#learnwithBrainly

8 0

3 years ago