State whether the following statement is true or false. If false, then rewrite
1. Melting of ice is a physical change.​

Answer:

theory

Explanation:

if you assume something that you didn't see occuring it is called a theory

Answer:

- Because it could lead to rise in sea levels which could cause heavy floods in the Small Island States and thus destroy their economies.

Explanation:

The reason is that too much carbon dioxide emissions trapped in the atmosphere can cause global worming which includes climate change and rise in sea levels.

Now, due to the fact that we know islands are lands surrounded by water, a rise in sea level of by as small as 1 metre could be very dangerous to these small islands in that they could cause them to become flooded and thus cause harm to lives and properties thereby damaging their economies.

Explanation:

The easiest method to separating magnets is to slide them apart. When separating magnets keep in mind shear force. Magnets are measured on pull strength, so are up to five times easier to move if they are pushed apart instead of pulled apart. Small magnets slide relatively easily, even without spacers.

Firmly slide them away from each other and far enough apart so that they don't hop back together. Neodymium magnets are quite strong.

The properties of the magnet are:

Thus,  slide them away from each other and far enough apart so that they don't hop back together.

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Answer:

The answer would be [HCIO][OH-]

_________

[CIO-]

Explanation:

So, the answer would be (b).

Answer:

3. The mass of ethanol required is approximately 0.522869 g

The mass of ethanoic acid required is approximately 0.68156 g

4. The mass of iron (III) oxide required is approximately 285.952.189.095 tonnes

5. The mass of silver nitrate required is approximately 14.53 grams

6. The mass of copper oxide that would be needed is approximately 31.86 grams

7. a. The mass of the precipitate, Zn(OH)₂ formed is approximately 49.712 grams

b. The mass of the precipitate, Al(OH)₃ formed is approximately 13 grams

c. The mass of the precipitate, Mg(OH)₂, formed is approximately 14.579925 grams

Explanation:

3. The 1 mole of ethanol and 1 mole of ethanoic acid combines to form 1 mole of ethyl ethanoate

The number of moles of ethyl ethanoate in 1 gram of ethyl ethanoate, n = 1 g/(88.11 g/mol) = 1/88.11 moles

∴ The number of moles of ethanol = 1/88.11 moles

The number of moles of ethanoic acid = 1/88.11 moles

The mass of ethanol = (46.07 g/mol) × 1/88.11 moles = 0.522869 g

The mass of ethanoic acid in the reaction = 60.052 g/mol × 1/88.11 moles ≈ 0.68156 g

4. 1 mole of iron(III) oxide reacts with 1 mole of CO₂ to produce 1 mole of iron

The number of moles in 100 tonnes of iron= 100000000/55.845 = 1790670.60614 moles

The mass of iron (III) oxide required = 159.69 × 1790670.60614 = 285952189.095 g ≈ 285.952.189.095 tonnes

5. The number of moles of NaCl in 5 grams of NaCl = 5 g/58.44 g/mol = 0.0855578371 moles

The mass of silver nitrate required, m = 169.87 g/mol × 0.0855578371 moles ≈ 14.53 grams

6. The number of moles of CuSO₄·5H₂O in 100 g of CuSO₄·5H₂O = 100 g/(249.69 g/mol) ≈ 0.4005 moles

The mass of copper oxide required, m = 79.545 g/mol × 0.4005 moles ≈ 31.86 grams

7. a. The number of moles of NaOH in the reaction = 20 g/(39.997 g/mol) ≈ 0.5 moles

2 moles of NaOH produces 1 mole of Zn(OH)₂

0.5 moles of NaOH will produce 0.5 mole of Zn(OH)₂

The mass of 0.5 mole of Zn(OH)₂ = 0.5 mole × 99.424 g/mol = 49.712 grams

The mass of the precipitate, Zn(OH)₂ formed = 49.712 grams

b. 6 moles of NaOH produces 2 moles Al(OH)₃

20 g, or 0.5 mole of NaOH will produce (1/6) mole of Al(OH)₃

The mass of the precipitate, Al(OH)₃ formed, m = 78 g/mol×(1/6) moles = 13 grams

c. 2 moles of NaOH produces 1 mole of Mg(OH)₂, therefore;

20 g or 0.5 moles of NaOH formed (1/4) mole of Mg(OH)₂

The mass of the precipitate, Mg(OH)₂, formed, m = 58.3197 g/mol × (1/4) moles = 14.579925 grams

Answer:

Explanation:

i will show in details how 2 do the 1st Q n u can do the rest by following the way how it is done

3. given C^2H^5OH + CH^3CO^2H → CH^3CO^2C^2H^5 + H^2O

molar ratio of ethanol, ethanoic acid and ethyl ethanoate is 1 : 1 : 1

so mass = no. of moles * molecular mass

for same no. of moles, mass / molecular mass is the same

molecular mass of CH^3CO^2C^2H^5 = 12+1*3+12+16*2+12*2+5*1 = 88

molecular mass of C^2H^5OH = 12*2+1*5+16+1 = 46

molecular mass of CH^3CO^2H = 12+1*3+12+16*2+1 = 60

1 g of ethyl ethanoate = 1/88 mole

it requires 1/88*46 = 0.5227 g of ethanol; and

1/88*60 = 0.6818 g of ethanoic acid

to react together to form 1 g of ethyl ethanoate

Answer:

carbon

Explanation:

because it is an allotrope of carbon

Answer:

Carbon

Explanation:

its literaly carbon

Answer: The mass density is 1166.36 [tex]kg/m^{3}[/tex].

Explanation:

Given: Weight of sample in air [tex](F_{air})[/tex] = 500 N

Weight of sample in alcohol [tex](F_{alc})[/tex] = 200 N

Specific gravity = 0.7 = [tex]0.7 \times 1000 = 700 kg/m^{3}[/tex]

Formula used to calculate Buoyant force is as follows.

[tex]F_{B} = F_{air} - F_{alc}\\= 500 - 200 \\= 300 N[/tex]

Hence, volume of the material is calculated as follows.

[tex]V = \frac{F_{B}}{\rho \times g}[/tex]

where,

[tex]F_{B}[/tex] = Buoyant force

[tex]\rho[/tex] = specific gravity

g = acceleration due to gravity = 9.81

Substitute the values into above formula.

[tex]V = \frac{F_{B}}{\rho \times g}\\= \frac{300}{700 \times 9.81}\\= \frac{300}{6867}\\= 0.0437 m^{3}[/tex]

Now, mass of the material is calculated as follows.

[tex]mass = \frac{F_{air}}{g}\\= \frac{500 N}{9.81}\\= 50.97 kg[/tex]

Therefore, density of the material or mass density is as follows.

[tex]Density = \frac{mass}{volume}\\= \frac{50.97 kg}{0.0437 m^{3}}\\= 1166.36 kg/m^{3}[/tex]

Thus, we can conclude that the mass density is 1166.36 [tex]kg/m^{3}[/tex].

Answer:

all i can accurately say is that 2 and 4 are both true

Answer: The vapor pressure of ethanol at [tex]26.3^{o}C[/tex] is 238.3 torr.

Explanation:

Given: [tex]\Delta H_{vap}[/tex] = 38.6 kJ/mol

[tex]T_{1} = 26.3^{o}C = (26.3 + 273) K = 299.3 K[/tex]

[tex]T_{2} = 78.4^{o}C = (78.4 + 273) K = 351.4 K[/tex]

Formula used to calculate the vapor pressure of ethanol is as follows.

[tex]ln\frac{P_{2}}{P_{1}} = \frac{\Delta H_{vap}}{R} [\frac{1}{T_{1}} - \frac{1}{T_{2}}]\\[/tex]

Substitute the values into above formula as follows.

[tex]ln\frac{P_{2}}{P_{1}} = \frac{\Delta H_{vap}}{R} [\frac{1}{T_{1}} - \frac{1}{T_{2}}]\\ \\ln \frac{760 torr}{P_{1}} = \frac{38600 J}{8.314 J/mol K}[\frac{1}{299.3} - \frac{1}{351.4}]\\\frac{760}{P_{1}} = 3.18\\P_{1} = 238.3 torr[/tex]

Thus, we can conclude that the vapor pressure of ethanol at [tex]26.3^{o}C[/tex] is 238.3 torr.

Answer:

(i) specific heat

(ii) latent heat of vaporization

(iii) latent heat of fusion

Explanation:

i. Q = mcΔT; identify c.

Here, Q is heat, m is the mass, c is the specific heat and ΔT is the change in temperature.

The amount of heat required to raise the temperature of substance of mass 1 kg by 1 degree C is known as the specific heat.  

ii. Q = mLvapor; identify Lvapor

Here, Q is the heat, m is the mass and L is the latent heat of vaporization.

The amount of heat required to convert the 1 kg liquid into 1 kg vapor at constant temperature.  

iii. Q = mLfusion; identify Lfusion

Here, Q is the heat, m is the mass and L is the latent heat of fusion.  

Here, Q is the heat, m is the mass and L is the latent heat of vaporization.

The amount of heat required to convert the 1 kg solid  into 1 kg liquid at constant temperature.  

(i) c is the molar heat capacity of the substance.

(ii) Lvapor is the latent heat of evaporation of the substance

(iii) Lfusion is the latent heat of fusion of the substance

All the 3 equations fall under Calorimetry.

In all the equation Q is the amount of heat required.

(i) First equation represents the amount of heat required to raise the temperature of a substance of mass m.

                          Q = mcΔT

       here c is the molar heat capacity of the substance and ΔT is the chnage in temperature.

(ii) Second equation represents the amount of heat required to convert a substance of mass m from liquid phase to vapour phase.

                          Q = mLvapor

        here Lvapor is the latent heat of evaporation of the substance

during evaporation no change in temperature occurs.      

(iii) Third equation represents the amount of heat required to convert a substance of mass m from solid phase to liquid phase.

                          Q = mLfusion

        here Lfusion is the latent heat of fusion or melting of the substance

during fusion no change in temperature occurs.    

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Answer:

Metals , silver and copper which allows to pass the electricity through it is called good conductor of electricity .

hope it is helpful to you ☺️

Answer:

25.6g de HF son producidos

Explanation:

...¿Cuánto HF es producido?

Para resolver este problema debemos convertir la masa de cada reactivo a moles usando su masa molar. Como la reacción es 1:1, el reactivo con menor número de moles es el reactivo limitante. Con las moles del reactivo limitante podemos obtener las moles de HF y su masa así:

Moles CaF2:

Masa molar:

1Ca = 40g/mol

2F = 19*2 = 38g/mol

40+38 = 78g/mol

50g CaF2 * (1mol/78g) = 0.641 moles CaF2

Moles H2SO4:

Masa molar:

2H = 2g/mol

1S = 32g/mol

4O = 64g/mol

98g/mol

100g H2SO4 * (1mol / 98g) = 1.02 moles H2SO4

Como las moles de CaF2 < Moles H2SO4: CaF2 es reactivo limitante.

Moles HF usando la reacción:

0.641 moles CaF2 * (2mol HF / 1mol CaF2) = 1.282 moles HF

Masa HF:

Masa molar:

1g/mol + 19g/mol = 20g/mol

1.282 moles HF * (20g/mol) =

Answer:

The pyruvate dehydrogenase kinase enzyme activity would increase, resulting in an inhibition of pyruvate dehydrogenase activity. ... An in vitro study shows that isocitrate dehydrogenase is activated in the citrate cycle.

Explanation:

Answer:

I hope that's what u were lookong for :))

Explanation:

Answer:

ns - time

12g/ml - density

1.8pm - length

250m2 - area

325K - temperature

5.4mL - volume

90kg - mass

Explanation:

The unit of measurement is used to identify what a measurement is. It is very important to place a specific unit for each measurement made as it distinguishes them from one another. In this question, various measurements were given, which can be identified using their units.

- ns is measurement for time because seconds (s) is its unit

- 12g/ml is measurement for density because grams/milliliters (g/mL) is its unit

- 1.8pm is measurement for length because length can be measured in picometer (pm).

- 250m2 is measurement for area because metre² (m²) is its unit.

- 325K is measurement for temperature because Kelvin is the absolute unit for temperature.

- 5.4mL is measurement for volume because volume can be measured in milliliters (ml).

- 90kg is measurement for Mass because kilograms (s) is its unit.

Answer: Solution D has the highest concentration of all.

Explanation:

The formula used to calculate molarity:

[tex]\text{Molarity of solution}=\frac{\text{Moles of solute}\times 1000}{\text{Volume of solution (mL)}}[/tex]  .....(1)

Molarity of permanganate solution = 0.1 M

Volume of solution = [tex]100 cm^3=100mL[/tex]        (Conversion factor: [tex]1mL=1cm^3[/tex])

Putting values in equation 1, we get:

[tex]0.1=\frac{\text{Moles of permanganate solution}\times 1000}{100}\\\\\text{Moles of permanganate solution}=\frac{100\times 0.1}{1000}=0.01mol[/tex]

Molarity of permanganate solution = 0.01 M

Volume of solution = [tex]100 cm^3=100mL[/tex]

Putting values in equation 1, we get:

[tex]0.01=\frac{\text{Moles of permanganate solution}\times 1000}{100}\\\\\text{Moles of permanganate solution}=\frac{100\times 0.01}{1000}=0.001mol[/tex]

Molarity of permanganate solution = 2 M

Volume of solution = [tex]100 cm^3=100mL[/tex]

Putting values in equation 1, we get:

[tex]2=\frac{\text{Moles of permanganate solution}\times 1000}{100}\\\\\text{Moles of permanganate solution}=\frac{100\times 2}{1000}=0.2mol[/tex]

Molarity of permanganate solution = 2.5 M

Volume of solution = [tex]100 cm^3=100mL[/tex]

Putting values in equation 1, we get:

[tex]2.5=\frac{\text{Moles of permanganate solution}\times 1000}{100}\\\\\text{Moles of permanganate solution}=\frac{100\times 2.5}{1000}=0.25mol[/tex]

The solution having the highest number of moles will have the highest concentration for the same volume.

Thus, solution D has the highest concentration of all.

Answer:

D. Burning a peice of wood

Explanation:

Because when you burn wood a chemical reaction happenes between the flames and the wood making the wood into ashes.

Hope this helps you :)

The dissolving salt in water is an an example of a chemical change. The correct option is A.

A chemical change, also known as a chemical reaction, is the production of new substances with changing chemical compositions and characteristics.

In water, sodium chloride dissociates into Na+ ions and Cl- ions, which may be described as a chemical process.

The ionic connections between the atoms are broken as salt dissolves. Because the reactant (sodium chloride or NaCl) varies from the products (sodium and chloride ions), a chemical reaction takes place.

Thus, the correct option is A.

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Answer: where is the deephorizon slice at ?

Explanation:

Answer:

calcium is the correct answer to the question

La respuesta correcta para esta pregunta abierta es la siguiente.

Desafortunadamente, no anexas opciones o incisos para contestar la pregunta.

Sin embargo, podemos comentar lo siguiente.

¿A qué se llama Recursos químicos en Química Industrial? ¿Cómo logran convertirse en bienes de consumo para la sociedad?

Hablando de Química Industrial, los recursos químicos son todos aquellos recursos que se utilizan para la extracción, procesamiento, y fabricación de los recursos naturales y materias primas para la elaboración de productos que posteriormente serán utilizados por otras industrias para ofrecerlas y venderlas como productos para el consumo masivo de las personas.

Este procesamiento de substancias para transformarlas en productos de consumo en general va encaminado a beneficiar a diferentes sectores como la medicina, los endulzantes, los fertilizantes, los saborizantes, los insecticidas, los plaguicidas, colorantes, y todo tipo de sustancia que pueda ser industrializada para su consumo final.

Answer:

a

Explanation:

I'm not completely sure tho veary sorry if it's wrong

Answer:

the answer is C

Explanation:

as the yeast feeds on sugar and yields the ATP per glucose molecule and Carbon dioxide

Answer: Because when you blow air /gas into a balloon you fill it with air particles ,so they more you blow u blow in more air particles so they tend to collide with each other ,so as they hit the walls of the balloons pressure is exerted ,so the pressure keeps the balloon inflated with its shape

Answer:

Nice and you

Explanation:

Please Mark me brainliest

Answer:

The height of a column of ethanol is 13.1m

Explanation:

we begin by converting the density to SI unit= 0.789g/cm3* 1kg * [tex]100^{3}[/tex]* [tex]cm^{3}[/tex]

                                                                               cm * 1000g * [tex]1^{3}m^{3}[/tex]

                                                            = 789kg/m3

converting pressure to SI unit= 1 atm =101325 Pa

hence P= hdg

g= 9.81 m/s2

making h the subject of the formula

h= P/dg

h= 101325Pa/ 789kg/m3 * 9.81 m/s2

h= 13.1m

Answer:

A) Less than 1%

Explanation:

The answer is approximately 0.04%

Answer:

the process by which green plants and some other organisms use sunlight to synthesize nutrients from carbon dioxide and water. Photosynthesis in plants generally involves the green pigment chlorophyll and generates oxygen as a by-product.

Answer:

the process by which green plants and some other organisms use sunlight to synthesize nutrients from carbon dioxide and water. Photosynthesis in plants generally involves the green pigment chlorophyll and generates oxygen as a by-product.

Answer:

CH2O

Explanation:

According to this question:

C = 2.04g

H = 0.34g

O = 2.73g

First, we divide the mass value of each element by its atomic mass to convert to moles.

C = 2.04g ÷ 12 = 0.17mol

H = 0.34g ÷ 1 = 0.34mol

O = 2.73g ÷ 16 = 0.17mol

Next, we divide by the smallest mole value (0.17):

C = 0.17mol = 0.17 = 1

H = 0.34mol ÷ 0.17 = 2

O = 0.17mol ÷ 0.17 = 1

The whole number ratio of C,H,O is 1:2:1, hence, the empirical formula is CH2O.