Chemistry, 20.09.2020 02:01 makennahudson94

An object is a regular, rectangular, solid with dimensions of 2 cm by 3cm by 2cm. It has a mass of 24 g. Find its density.

Answers: 2

Show answers

Answers

Answer from: Queey

$\boxed {\tt d= 2 \ g/cm^3}$

Explanation:

Density can be found using the following formula.

$d=\frac{m}{v}$

where is the mass and is the volume.

We know the mass is 24 grams. We must find the volume.

Since it is a rectangle, the volume can be found using the following formula.

v=l*w*h

The length is 2 centimeters, the width is 3 centimeters and the height is 2 centimeters.

$v= 2 \ cm * 3 \ cm * 2\ cm$

$v= 6 \ cm^2 * 2\ cm$

$v= 12 \ cm^3$

Now we know the volume, and can substitute it into the density formula.

$d=\frac{m}{v}$

$m= 24 \ g\\v= 12 \ cm^3$

$d=\frac{24 \ g}{12 \ cm^3}$

$d= 2 \ g/cm^3$

The density is 2 grams per cubic centimeter.

Answer from: Quest

water molecules stay close to each other through cohesion, the collective action of hydrogen bonds between water molecules. cohesion plants draw water upwards from the root through the stem's transport tubes (xylem) to the leaf. this transport occurs even in large trees and against gravity. transpiration, evaporation of water from plant leaves, creates a tension on water molecules being pulled up from the stem and roots.

water also has high (the attraction of one substance to another) properties because of its polar nature. adhesion of water molecules to plant cell walls counteract gravity while water is transported from roots to leaves.

water exhibits a very high surface tension when compared to other liquids. surface tension is a property of a liquid that holds the surface together and allows it to resist an external force. by capillary action, the water forms concave menisci inside the pores. the high surface tension of water pulls the concavity outwards, generating enough force to lift water from the roots to the leaves of plants.

thus, cohesion, along with adhesion and surface tension creates a capillary action that keeps water molecules interacting and moving through the plants out to the leaf cells.

therefore, option d) is the correct answer.

explanation:

Answer from: Quest

answer: the value of enthalpy change will be -152.80 kj.

solution:

pressure = 1atm , temperature = $25^oc$ = 298 k $)0^oc=273kelvins$

$o_3+3no\rightarrow 3no_2,\delta h_{reaction}=? [/)</p><p>[tex]\delta h_{no}=90.4kj/mol$

$\delta h_{no_2}=33.85kj/mol$

$\delta h_{o_3}=142.2kj/mol$

$\delta h_{reaction}=\sum \delta h_{products}-\sum\delta h_{reactants}=3\times\delta h_{no_2}-(3\times \delta h_{no}+\delta h_{o_3})$

$\delta h_{reaction}=33.85-(90.4+142.2)=-311.85kj/mol$

given that pressure and temperature are same in both gases , the number of moles of both gases can be determined by the ideal gas equation.

$v_{no}=12.00 l,v_{o_3}=8.50 l$

$pv_{no}=n_{no}rt=1atm \times 12.00 l=n_{no}\times 0.0821 atml/k mol \times 298 k$

$n_{no}=0.49 moles$

$pv_{o_3}=n_{o_3}rt=1atm \times 8.50 l=n_{o_3}\times 0.0821 atml/k mol \times 298 k$

$n_{o_3}=0.34 moles$

according to reaction 3 moles no are reacting with 1 mol of $o_3$ ,then 0.49 mol of no will react with $\frac{1}{3}\times 0.49$ moles of ozone that is 0.16 moles of ozone. since, no is limiting reagent and $o_3$ is an excessive reagent.

enthalpy change for the reaction between the given volumes of the gases is :

$\delta h_{reaction}\times \text{moles of no}=-311.85kj/mol\times 0.49 mol=-152.80kj/mol$

Another question on Chemistry

Chemistry, 22.06.2019 11:20

Which fact represents evidence for the big bang theory?

Answers: 2

Answer

Chemistry, 22.06.2019 20:00

How many moles are in 123.0 grams of kclo4?

Answers: 1

Answer

Chemistry, 22.06.2019 22:30

How many moles of kci are produced from 2.50 moles k

Answers: 1

Answer

Chemistry, 22.06.2019 23:30

With the largest atoms and the smallest number of valence electrons and with the smallest atoms and the greatest number of valence electrons are the most reactive. a. nonmetals; metals b. nonmetals; transition elements c. transition elements; metals d. metals; nonmetals

Answers: 3

Answer

You know the right answer?

An object is a regular, rectangular, solid with dimensions of 2 cm by 3cm by 2cm. It has a mass of...

Questions