Explain why heat is often used in a laboratory experiment. a. To warm up the laboratory, b. To speed up a reaction

Answer:

yes!!!!!!!!!!

Explanation:

now go learn    son

Answer:

No, it acts only as a reducing agent

Explanation:

Sulphur dioxide is a strong reducing agent. It is mainly used to prevent dried fruit from being oxidised and discoloured.

Answer:

Explanation:

The density of a substance can be found by using the formula

[tex]Density = \frac{mass}{volume} [/tex]

From the question

mass of copper = 89.6 g

volume = 10 cm³

Substitute the values into the above formula and solve

That's

[tex]Density = \frac{89.6}{10} [/tex]

We have the final answer as

Hope this helps you

Answer:

[tex]W = 6.65 \cdot 10^{6} lbf[/tex]

Explanation:

To find the weight (W) of the pond contents first we need to use the following equation:

[tex] W = m\cdot g [/tex]   (1)

Where m the mass and g is the gravity  

Also, we have that the mass is:

[tex]m = \rho*V[/tex]  (2)    

Where ρ is the density and V the volume

We cand calculate the volume as follows:

[tex] V = L*w*d [/tex]   (3)

Where L is the length, w is the wide and d is the depth  

By entering equation (2) and (3) into (1) we have:

[tex]W = \rho*L*w*d*g[/tex]

[tex] W = 75.3 lbm/ft^{3}*50 m*25 m*2 m*9.81 m/s^{2} [/tex]  

[tex]W = 75.3 lbm/ft^{3}*\frac{(1 ft)^{3}}{(0.3048 m)^{3}}*\frac{0.454 kg}{1 lbm}*50 m*25 m*2 m*9.81 m/s^{2} = 2.96 \cdot 10^{7} N}*\frac{0.2248 lbf}{1 N} = 6.65\cdot 10^{6} lbf[/tex]              

Therefore, the weight of the pond is 6.65x10⁶ lbf.

I hope it helps you!

Answer:

ot means that contains only one kind of matter. 

Answer:

a. 1720.

b. 0.0907.

Explanation:

Hello,

In this case, when translating scientific notation to standard notation one should move the decimal place the times the power indicates, that is for a, three places to the right (add zeros to complete it) and for b, two places to the left, therefore, we obtain:

a. 1720.

b. 0.0907.

Best regards.

Answer:

495 pm (see the relationship between the edge length (a) and radius (r) of atoms in attachment).

Explanation:

A crystalline solid possess rigid and long-range order; its atoms, molecules, or ions occupy specific positions. A unit cell is the basic repeating structural unit of a crystalline solid. Each sphere in the unit cell represents an atom, ion, or molecule and is called a lattice point. The way the spheres are arranged in layers determines what type of unit cell we have.

In the face-centered cubic cell, there are spheres at the center of each of the six faces of the cube, in addition to the eight corner spheres (see the second picture in the attachment). Each sphere in this arrangement is said to have a coordination number of 12 since each sphere is in contact with six spheres in its own layer, three spheres in the layer above, and three spheres in the layer below. The coordination number is defined as the number of atoms (or ions) surrounding an atom (or ion) in a crystal lattice.

In the first picture in the attachment we can see that the relationship between the atomic radius r and the  edge length a face-centered  cubic cell is:

a=√8*r

Therefore, the edge length will be √8*175 pm = 495 pm

FCC Stands for Face Centered Cubic

The formula that is used to find edge length is:

[tex]a=\sqrt{8}*r[/tex]

where

a= edge length

r= radius

Given:

r= 175 pm

Substituting the values in the above formula.

[tex]a=\sqrt{8}*175\\\\a=495 pm[/tex]

Therefore, the edge length will be 495 pm.

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Answer:

dispersion.

Explanation:

The molecule, PF2Cl3 is trigonal bipyramidal. The dipoles in the molecule cancel out since there is a symmetric charge distribution around the molecule hence the resultant dipole moment of the molecule is zero.

If the molecule is nonpolar, then the dominant intermolecular forces present are the weak dispersion forces, hence the answer above.

Answer:

[tex]m_{HNO_3}=27.4gHNO_3[/tex]

Explanation:

Hello,

In this case, for the chemical reaction:

[tex]3 NO_2(g) + H_2O(l) \rightarrow 2 HNO_3(aq) + NO(g)[/tex]

The first step is to compute the theoretical yield of nitric acid via stoichiometry in terms of the 3:2 ratio between nitrogen dioxide (molar mass = 46 g/mol) and nitric acid (molar mass = 63 g/mol) respectively:

[tex]m_{HNO_3}^{theoretical}=40.0gNO_2*\frac{1molNO_2}{46gNO_2}* \frac{2molHNO_3}{3molNO_2} *\frac{63gHNO_3}{1molHNO_3} \\\\m_{HNO_3}^{theoretical}=36.52gHNO_3[/tex]

Now, the actual amount is computed by taking into account the 75.0-% percent yield:

[tex]m_{HNO_3}=0.75*36.5gHNO_3\\\\m_{HNO_3}=27.4gHNO_3[/tex]

Best regards.

Answer:

2.954grams of pottasium for that week

Explanation:

According to this question, a medium-sized that weighs 118grams contains 422 milligrams (mg) of potassium nutrient.

If someone eats a medium-sized banana each day for a week, this means that the person has consumed 422mg of pottasium that day.

Since there are 7days in a week, the person will consume 422 × 7 = 2954 mg of pottasium that week.

The question asks for the total pottasium intake in grams for that week, hence, we need to convert 2954 milligrams to grams.

1000mg = 1 g

Hence, 2954mg will be 2954/1000

= 2.954grams

Therefore, 2.954grams of pottasium are ingested by that person that week.

Answer:

2450 cm3

Explanation:

Volume of cylinder = V=πr2h

2.45L = 2450mL

1mL = 1 cm cubed

2450mL = 2450 cm cubed

The volume of the cylinder container in cubic centimeters is 2.45 × 10³ cm³.

We usually can find the volume of a cylinder applying the following expression.

[tex]V = \pi r^{2} h[/tex]

where,

Since we don't know the height, we will have to use the information that it can hold 2.45 L of water. We can convert liters to cubic centimeters using the following conversion factors:

[tex]2.45 L \times \frac{1000mL}{1L} \times \frac{1cm^{3} }{1mL} =2.45 \times 10^{3} cm^{3}[/tex]

The volume of the cylinder container in cubic centimeters is 2.45 × 10³ cm³.

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Answer:

3/5

Explanation:

Answer:

[tex]\rho =10.07\frac{lb}{cup}[/tex]

Explanation:

Hello,

In this case, given that 1 cup equals 236.588 mL and 1 pound equals 453.6 g, the required density in pounds per cup turns out:

[tex]\rho =19.3\frac{19.3g}{mL}*\frac{1lb}{453.6g}*\frac{236.588mL}{1cup}\\ \\\rho =10.07\frac{lb}{cup}[/tex]

Best regards.

Answer:

The symbol of each element is, Ne, Na, Mg, and Al.

Explanation:

Below is the list of elements that has an atomic mass of less than 19.3 u.

The atomic mass of Neon is 20.1797 u and the atomic number is 10.

The atomic mass of Sodium is 22.989769 u and the atomic number is 11.

The atomic mass of Magnesium is 24.305 u and the atomic number is 12.

The atomic mass of Aluminium is 26.981539 u and the atomic number is 13.

Here, the symbol of each element is, Ne, Na, Mg, and Al.

Answer:

14.83mL

Explanation:

11.6/0.81=14.3

Answer:  The correct answer would be : "A bottle that is sealed".

I hope that this helps you !

A 1-L soda bottle contains dissolved carbon dioxide gas then the bottle which have the highest concentration of dissolved gas is a bottle that is sealed.

Carbon dioxide is easily dissolved in water or soda to make tiny bubbles and it prevents the growth of bacteria during the preservation of sodas.

This dissolved carbon dioxide gas coming out in the form of effervescence when we open a bottle of soda. So, in the sealed bottle of soda higher concentration of dissolved carbon dioxide gas is present. And if we open the seal then the amount of dissolved carbon dioxide decreases from the bottle.

Hence option (A) is correct.

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Answer:

a. Conversion of A to C is exergonic.

Explanation:

In the problem:  C→ B occurs with ΔG = + 16 kJ/mol

It is possible to sum ΔG of reactions to obtain ΔG of another related reaction:

A → B ΔG = -14kJ/mol

C → B ΔG = +16kJ/mol

A → C ΔG = -14kJ/mol - (+16kJ/mol) = -30kJ/mol

As ΔG < 0

The reaction is exergonic

Under these condition, the reaction occurs. But under another conditions, the reaction will be at equilibrium (ΔG = 0)

A reaction is entropically driven if ΔG < 0 and ΔS is high. But we don't have information of ΔS.

As ΔG <0, the reaction is not spontaneous in the reverse direction

Right option is:

Answer:

A. Ne, Br, Ca, Ba

Explanation:

Ionization energy is the minimum amount of energy required to remove n electron from an atom.

The general trend is increase in moving from left to right across periods in the periodic table and decreasing down the group.

Barium, Ba belongs to period 6, so it is expected to have the lowest ionization energy.

Neon, Ne belongs to period 2, it would have the highest ionization energy.

Calcium, Ca and Bromine, Br both belongs to the same period, however bromine is in group 7, bromine would have the higher ionization energy.

Inorder of decreasing ionzation enrgy;

Ne, Br, Ca, Ba

Answer:

a human mat not be able to reproduce

Explanation:

i think this is right

Answer:

See explanation

Explanation:

The density of an irregular object can be determined using a graduated cylinder, water and a balance as follows.

The irregularly shaped object is weighed in a balance and its mass is recorded. The graduated cylinder is then filled with a given volume of water. This volume of water is also recorded. The irregularly shaped object is then introduced into the graduated cylinder containing the water and the change in volume of the water is recorded.

Volume of the object= change in volume of the water

Density= mass/volume

b)

If the beads weigh 50.217 g

Volume of beads = change in volume of water= 40.7 ml - 35.0ml = 5.7 ml

Density= mass/volume = 50.217 g/5.7 ml = 8.81 g/ml

Accepted value of the density of copper in g/ml = 8.94 g/ml

% error in density = |8.81-8.94|/8.94 ×100

% error in density = 1.45%

Answer:

Explanation:

The density of a substance can be found by using the formula

[tex]Density = \frac{mass}{volume} [/tex]

From the question

mass = 50 g

volume = 30 mL

Substitute the values into the above formula and solve for the density

That's

[tex]Density = \frac{50}{30} \\ = \frac{5}{3} \\ = 1.66666...[/tex]

Wr have the final answer as

Hope this helps you

Answer:

www.doe.virginia.gov/testing/sol/standards_docs/...

Explanation:

did you get the answer??

Answer:

Endothermic

Explanation:

Storing sugar for later use is an example of an endothermic reaction because that energy is being absorbed.

Answer:

m=7.475 kg

Explanation:

Given that,

The density of tin is 5.75 g/cm³.

We need to find the mass of the object if the volume of the rectangular block is 1.3 L.

We know that,

1 L = 1000 cm³

1.3 L=1300 cm³

The formula of density,

[tex]\rho=\dfrac{m}{V}\\\\m=\rho\times V[/tex]

[tex]m=5.75\ g/cm^3\times 1300\ cm^3\\\\\m=7475\ g[/tex]

or

m=7.475 kg

So, the mass off the object is 7.475 kg.

WOW! I have the same question! Again lol.

A similarity is that both are at the same temperature and a difference is both are at different states of matter between the particles in liquid water at 100ºC and the particles in steam at 100ºC.

There are only 3 states in which matter is present in the universe that is solid, liquid and gas, and on the basis of molecular space, they are differentiated in their respective category.

The water present both at 100ºC first is in a liquid state where molecules of water are more close as compared to the molecules of the steam water but the temperature for both is the same.

Therefore, the similarity is that both are at the same temperature and a difference is both are at different states of matter between the particles in liquid water at 100ºC and the particles in steam at 100ºC.

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Answer:

1. Polar

2 nonpolar

3. Nitrogen or oxygen

4.carbon

5.Repelled by and attracted to

Answer:

a. 0.0178 moles of KBr

0.0178 moles of K

0.0178 moles of Br

b.  1.52×10⁻³ moles of acid

4.55×10⁻³ moles of H

1.52×10⁻³ moles of P

6.07×10⁻³ moles of O

c. 229.8 moles of calcium carbonate

229.8 moles of Ca

229.8 moles of C

689.4 moles of O

d. 0.229 moles of aluminum sulfate

0.458 moles of Al

0.687 moles of S

2.75 moles of O

e. 6.43×10⁻⁷ moles of C₈H₁₀N₄O₂

5.14×10⁻⁶ moles of C

6.43×10⁻⁶ moles of H

2.57×10⁻⁶ moles of N

1.28×10⁻⁶ moles of O

Explanation:

To determine the moles of each compound we need to know the molar mass of them

Subscripts number of compounds are the number of moles, of each atoms.

For example, H₂O. 1 mol of water has 2 moles of H and 1 mol of O.

a. KBr → 119 g/mol

We convert the mass to moles (mass/molar mass)

2.12 g / 119 g/mol = 0.0178 moles of bromide

1 mol of potassium bromide has 1 mol of K and 1 mol of Br, then 0.0178 moles of salt, will have:

0.0178 moles of K

0.0178 moles of Br

b. H₃PO₄ → 97.97 g/mol

0.1488 g / 97.97 g/mol = 1.52×10⁻³ moles of acid.

1 mol of phosphoric acid has 3 moles of H, 1 mol of P and 4 moles of O

Then 1.52×10⁻³ moles of acid. will have:

(1.52×10⁻³ . 3) / 1 = 4.55×10⁻³ moles of H

1.52×10⁻³ moles of P

(1.52×10⁻³ . 4) / 1 = 6.07×10⁻³ moles of O

c. CaCO₃ → 100.08 g/mol

23000g / 100.08 g/mol = 229.8 moles

(notice, we convert the kg to g, before)

1 mol of calcium carbonate has 1 mol of Ca, 1 mol of C and 3 moles of O

Then 229.8 moles of salt will have

229.8 moles of Ca

229.8 moles of C

(229.8 . 3) / 1 = 689.4 moles of O

d. Al₂(SO₄)₃ → 342.15 g/mol

78.452 g / 342.15 g/mol = 0.229 moles

1 mol of Al₂(SO₄)₃ has 2 moles of Al, 3 moles of S and 12 moles of O

Then  0.229 moles of sulfate will have:

(0.229 . 2) / 1 = 0.458 moles of Al

(0.229 . 3) / 1 = 0.687 moles of S

(0.229 . 12) / 1 = 2.75 moles of O

e. C₈H₁₀N₄O₂  → 194.19 g/mol

0.0001250 g / 194.19 g/mol = 6.43×10⁻⁷ moles

(Notice, we convert mg to g)

1 mol of caffeine has 8 moles of C, 10 moles of H, 4 moles of N and 2 moles of O

Then, 6.43×10⁻⁷ moles of caffeine will have:

(6.43×10⁻⁷ . 5) / 1 = 5.14×10⁻⁶ moles of C

(6.43×10⁻⁷ . 10) / 1 = 6.43×10⁻⁶ moles of H

(6.43×10⁻⁷ . 4)/1 = 2.57×10⁻⁶ moles of N

(6.43×10⁻⁷ . 2)/ 1 = 1.28×10⁻⁶ moles of O

Answer:

a

Explanation:

a the answers you welcome

The likely formulas for the molecules are NH₄OH, AlCl₃, CF₂Cl₂, CH₃O.

According to the context, the term may or may not include ions that meet this requirement. A molecule is a collection of two or more atoms held together by the attractive forces known as chemical bonds.

A molecule is the smallest unit of any material that is composed of one or more elements and is capable of existing independently while maintaining all the substance's physical and chemical properties. Further atom division occurs within molecules. For instance, the symbols for the oxygen atom and molecule are O and O2, respectively.

The smallest identifiable unit into which a pure substance may be divided while retaining its composition and chemical properties is a molecule, which is a collection of two or more atoms.

Thus, The likely formulas for the molecules are NH₄OH, AlCl₃, CF₂Cl₂, CH₃O.

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