LaKeisha is measuring the density of a solid piece of metal using the graduated cylinder method. She initially measures a volume of water in the cylinder to be 3.28 mL. After placing the metal into the graduated cylinder, the new volume was 8.72 mL. The mass of the metal was 42.26 g on a top loading balance.

Required:
What is the density of the metal calculated to the correct number of significant figures?

Answer:

c. KBr .

Explanation:

Hello!

In this case, since electrolytes are substances that are able to carry electric current in the form of electrons via ions, those that are ionic are said to have the greatest capacity to conduct the electricity; in such a way, since SO2, C6H12O6 and CO are non-ionic molecules but covalent, they are not good conductor, therefore the best conductor would be c. KBr as it is an ionic compound due to the electronegativity of the K-Br bond.

Best regards!

Answer:

B. KBr  + F2

Explanation:

In displacement reactions (reactions in which an element replaces another element in a compound) like these, reactive element displaces the less reactive element.

A. NaBr  +  I2  

This reaction will not occur because Iodine is not able to displace bromine from the compound.

B. KBr  + F2

This reaction will occur because flourine is more reactive and hence is able to displace bromine from the reaction.

C. LiF  +  Cl2

This reaction will not occur because chlorine is not able to displace flourine from the compound.

D. NaCl + I2

This reaction will not occur because Iodine is not able to displace Chlorine from the compound.

Answer: the answer is C Aluminum cans get crushed before recycling.

Explanation:

Answer:

it will option C because it had no change in chemical reaction

Answer:

its C

Explanation:

1/74.44 * 79.75 = 1.07

The molarity (mol/L) of NaClO in the bleach, given the data is 1.07 mol/L (Option C)

Molarity is defined as the mole of solute per unit litre of solution. Mathematically, it can be expressed as:

Molarity = mole / Volume

Mass of solute = percent × mass of solution

Mass of NaClO = 7.25% × 1100

Mass of NaClO = 0.0725 × 1100

Mass of NaClO = 79.75 g

Mole = mass / molar mass

Mole of NaClO = 79.75 / 74.44

Mole of NaClO = 1.07 mole

Molarity = mole / Volume

Molarity of NaClO = 1.07 / 1

Molarity of NaClO = 1.07 mol/L

Learn more about molarity:

https://brainly.com/question/9468209

#SPJ6

Answer:Acceleration due to gravity on the moon is 1/6 times as that on the earth and we know that mass is property of the material it always remains same and weight is measure of gravitational force, hence

mass of object on moon is 60kg and weight =60g/6=10×10=100N

Explanation:

Answer:

See explanation

Explanation:

A substance is classified as polar, nonpolar or ionic based on its behavior.

For the substances identified, there was no difficult in identifying each as  polar, nonpolar, or ionic because since it was quite to easy identify where each belongs by looking out for whether it mixes or dissolves in our experiment.

Every substance in the experiment either mixed or dissolved during the  experiment.

Answer:

look it updjk jkj vjx cv xckv

Explanation:

look it upvjcvjkcxjbvjkcvbjbcxkjvjdbfcvbdw uvd vjbvjfjv jdbv

Answer:

element :

a substance that is made up of only one type of atom

I hope it helps you ✌

Answer:

Maintenance of homeostasis usually involves negative feedback loops. These loops act to oppose the stimulus, or cue, that triggers them.

Answer:

0.864 g/mL.

Explanation:

I hope this helps u! also have a great rest of your day!

Answer:

Egypt

Explanation:

Hi again

Answer:

Explanation:

The aim of this question is to draw the structure of genistein and determine the number of atoms with sp² hybridization in the molecule.

From the image below, we will see the lewis structure of genistein. From the image, the blue asterisk atoms are sp² hybridized and the red marked atoms are sp³ hybridized.

We will also notice that all the carbon atoms contain 3 σ-bonds with no lone pair of electrons.

Using the knowledge of Valence shell electron repulsion theory (VSEPR), the above-mentioned carbon atom is said to be sp²hybridized.

Also, the oxygen atoms which are doubly bounded contains 1 σ-bond and 2 lone pair electrons. These oxygen atoms are also sp² hybridized.

Finally, the singly bonded oxygen atom is composed of 2 σ-bonds and 2 lone pair electrons. This makes it to be sp³ hybridized.

Altogether, we have a total of 16 sp² hybridized atoms and 4 sp³ hybridized atoms.

Answer:

The proportions in which the respective gases from each cylinder should be used; C1 : C2 : C3 = 1 : 2.308 : C3

Explanation:

Given that;

CH4 to C2H6 =  1.3 to 1

Cylinder 1 =  70% N2 and 30% CH3

Cylinder 2 = 90% N2 and 10% C2H6

Cylinder 3 = ( pure N2 ) = 100% N2

CH4 to C2H6 =  (1.3 to 1)

we have CH4 and C2H6 in cylinder 1 and 2 only

we only have balance material in c1 and c2

Now, Let x be from cylinder and ( 1-x ) be from cylinder 2

so, 30x / 10( 1-x ) = 1.3 / 1

30x = (10 - 10x)1.3

30x = 13 - 13x

30x + 13x = 13

x = 13/43

x = 0.3023

Also, ( 1-x ) = ( 1 - 0.3023) = 0.6977

so

C1/C2 = 0.3023/0.6977 = 1 / 2.308   while c3 can be anything;

Therefore, C1 : C2 : C3 = 1 : 2.308 : C3

Answer:

Q = 44.5 kJ

Explanation:

Given that,

Mass of water, m = 112 g

Water at 50.0°C cools to form ice at −45.0°C

We need to find the total amount of heat released. The formula for heat released is given by :

[tex]Q=mc\Delta T[/tex]

c is the specific heat of water, c = 4.184 J/g°C

So,

[tex]Q=112\times 4.184 \times (-45-50)\\\\Q=-44517.76\ J[/tex]

or

Q = -44.5 kJ

So, 44.5 kJ of heat is released.

Answer:

The arguments both for and against allowing genetically altered meats into the United States is explained below in details.

Explanation:

Arguments for and against genetically altered meats:

Answer:

The arguments both for and against allowing genetically altered meats into the United States is explained below in details.

Explanation:

Arguments for and against genetically altered meats:

Supply the Society. By 2050, the world's inhabitants are supposed to increase from today's 7 billion to way beyond 9 billion.

ENVIRONMENTAL RISK.

STRONGER CROPS = LESS PESTICIDES.

REMEMBER WHEN CIGARETTES WERE 'HARMLESS'?

TAMPERING FOR TASTE. ...

BIG BUSINESS EATS SMALL FARMERS.

ENHANCED HEALTH.

NOTHING TASTES BETTER THAN NATURE.

Explanation:

Answer:

20g or 0.2kg

Explanation:

this is because the mass of the powder is 20g and this will be added to the original mass of the milk causing it to increase by that amount

Answer: 20g

Explanation:

Answer:

it went under the process known as crystalization

Explanation:

am a chemist

Answer:

Distance between C-C in ethane- 1.54 Å

Distance between H atoms in eclipsed conformation-2.3 Å

Distance between H atoms in staggered conformation- 2.5 Å

Staggered conformation is more stable

Explanation:

The staggered conformation of ethane can be demonstrated as the most stable of conformation of ethane, because the angles between Carbon-Hydrogen bonds in both the front and back carbon atoms are maximized.  This now minimizes the energy of this conformation compared to the eclipsed conformation.

Considering the eclipsed conformation, it is obvious that the electron densities on Carbon-Hydrogen bonds come very close together thereby bringing two C-H bonds  into a dihedral angle of almost zero degrees. This causes their electron clouds to experience strong repulsion, thereby raising the molecules's total energy.

Answer:

See explanation below

Explanation:

There are several ways to know if an acid or base is strong. One method is calculating the pH. If the pH is really low, is a strong acid, and if it's really high is a strong base.

However we do not have a pH value here.

The other method is using bronsted - lowry theory. If an acid is strong, then his conjugate base is weak. Same thing with the bases.

Now, Looking at the 4 compounds, we can say that only two of them is weak and the other two are strong compounds. Let's see:

LiOH ---> Strong. If you try to dissociate :

LiOH ------> Li⁺ + OH⁻     The Li⁺ is a weak conjugate acid.

HF -----> Weak

HF --------> H⁺ + F⁻   The Fluorine is a relatively strong conjugate base.

HCl -----> Strong

This is actually one of the strongest acid.

NH₃ ------> Weak

Now writting the Ka and Kb expressions:

Ka = [H⁺] [F⁻] / [HF]

Kb = [NH₄⁺] [OH⁻] / [NH₃]

Finally, to calculate the [OH⁻] we need to use the following expression:

Kw = [H⁻] [OH⁻]

Solving for [OH⁻] we have:

[OH⁻] = Kw / [H⁺]

Remember that the value of Kw is 1x10⁻¹⁴. So replacing:

[OH⁻] = 1x10⁻¹⁴ / 7x10⁻⁶

[OH⁻] = 1.43x10⁻⁹ M

And now, multiplying by 10¹⁰ we have:

[OH⁻] = 1.429x10⁻⁹ * 1x10¹⁰

Hope this helps

Strong acids and bases are those which completely ionized in body fluid, and weak acids and bases are those who does not completely ionized in body fluid.

Ka expression is used to differentiate between strong and weak acids.

[tex]\bold{\dfrac{[H+][F-]}{[HF]}}[/tex]

[tex]\bold{\dfrac{[NH_4^+] [OH^-]}{[NH_3]} }[/tex]

Given, [tex]\bold{ [H^+]=1\times10^-^6\; at \;25^oC}[/tex]

We know, [tex]\bold{ [H^+]\times[OH^-]=1\times10^-^6\; at \;25^oC}[/tex]

[tex]\bold{[OH^-]=\dfrac{1\times10^-^1^4}{6.2\times10^-^6} = 1.43\times10^-^9}[/tex]

Now, multiplying the value by [tex]10^1^0[/tex]

[tex]\bold{( 1.429\times10^-^9) \times 1\times10^1^0= 14.29}[/tex]

Thus, the value is 14.29.

Learn more about acid and base, here:

https://brainly.com/question/10468518

Answer:

The blood sample has [H⁺] that is one million times lower than the [H⁺] of gastric juice.

Explanation:

To know the the correct answer to the question, we obtained obtained the hydrogen ion concentration [H⁺] of the blood and gastric juice. This can be obtained as follow:

For Blood sample:

pH = 7.4

Concentration of Hydrogen ion for blood [H⁺]₁ =?

pH = – Log [H⁺]₁

7.4 = – Log [H⁺]₁

Divide both side by –1

– 7.4 = Log [H⁺]₁

Take the antilog of – 7.4

[H⁺]₁ = Antilog (–7.4)

[H⁺]₁ = 3.98×10¯⁸ M

Thus, the concentration of Hydrogen ion for blood [H⁺]₁ is 3.98×10¯⁸ M

For Gastric juice:

pH = 1.4

Concentration of Hydrogen ion for gastric juice [H⁺]₂ =?

pH = – Log [H⁺]₂

1.4 = – Log [H⁺]₂

Divide both side by –1

– 1.4 = Log [H⁺]₂

Take the antilog of – 1.4

[H⁺]₂ = Antilog (–1.4)

[H⁺]₂ = 3.98×10¯² M

Thus, the concentration of Hydrogen ion for gastric juice [H⁺]₂ is 3.98×10¯² M

Finally, we shall compare the hydrogen ion concentration [H⁺] of the blood and gastric juice. This can be obtained as follow:

Concentration of Hydrogen ion for blood [H⁺]₁ = 3.98×10¯⁸ M

Concentration of Hydrogen ion for gastric juice [H⁺]₂ = 3.98×10¯² M

[H⁺]₁ / [H⁺]₂ = 3.98×10¯⁸ / 3.98×10¯²

[H⁺]₁ / [H⁺]₂ = 1×10¯⁶

Cross multiply

[H⁺]₁ = [H⁺]₂ × 1×10¯⁶

[H⁺]₁ = [H⁺]₂ / 1000000

From the calculations made above, the blood sample has [H⁺] that is one million times lower than the [H⁺] of gastric juice.

Answer:

I believe its C but it could be B

Answer:A

Explanation:  i would say the first one

Answer:

I would pipet 4 μl of each BSA work solution

Explanation:

To calculate the mass (in μg), we have to multiply the concentration C (in μg/ul) by the volume V (in μl):

C(μg/ul) x V( μl) = mass (μg)

We found the required volume for each solution, as follows:

5 μg/μl x V₁ = 20 μg ⇒ V₁ = 20 μg/(5 μg/μl ) = 4 μl

0.5 μg/μl x V₂ = 2 μg ⇒ V₂ = 2 μg/(0.5 μg/μl) = 4 μl

0.05 μg/μl x V₃ = 0.2 μg ⇒ V₃= 0.2 μg/(0.05 μg/μl) = 4 μl

Therefore, we need to pipet 4 μl of the solutions of concentrations 5μg/μl, 0.5 μg/μl, and 0.05 μg/μl to obtain the masses 20 μg, 2 μg, and 0.2 μg, respectively.

The given question is incomplete. The complete question is:

The change in entropy is related to the change in the number of moles of gas molecules. Determine the change in moles of gas for each of the reactions and decide if the entropy increases decreases or has little to no change:

A. [tex]K(s)+O_2(g)\rightarrow KO_2(s)[/tex]

B. [tex]CO(g)+3H_2(g)\rightarrow CH_4(g)+H_2O(g)[/tex]

C. [tex]CH_4(g)+2O_2(g)\rightarrow CO_2(g)+2H_2O(g)[/tex]

D. [tex]N_2O_2(g)\rightarrow 2NO(g)+O_2(g)[/tex]

Answer: A. [tex]K(s)+O_2(g)\rightarrow KO_2(s)[/tex] : decreases

B. [tex]CO(g)+3H_2(g)\rightarrow CH_4(g)+H_2(g)[/tex] : decreases

C. [tex]CH_4(g)+2O_2(g)\rightarrow CO_2(g)+2H_2O(g)[/tex]: no change

D. [tex]N_2O_2(g)\rightarrow 2NO(g)+O_2(g)[/tex] : increases

Explanation:

Entropy is defined as the randomness of the system.

Entropy is said to increase when the randomness of the system increase, is said to decrease when the randomness of the system decrease and is said to have no change when the randomness remains same.

In reaction [tex]K(s)+O_2(g)\rightarrow KO_2(s)[/tex], as gaseous reactant is changed to solid product, entropy decreases.

In reaction [tex]CO(g)+3H_2(g)\rightarrow CH_4(g)+H_2O(g)[/tex], as 4 moles of gaseous reactants is changed to 2 moles of gaseous product, entropy decreases.

In reaction [tex]CH_4(g)+2O_2(g)\rightarrow CO_2(g)+2H_2O(g)[/tex], as 3 moles of gaseous reactants is changed to 3 moles of gaseous product, entropy has no change.

In reaction  [tex]N_2O_2(g)\rightarrow 2NO(g)+O_2(g)[/tex] , as 1 mole of gaseous reactant is changed to 3 moles of gaseous product, entropy increases.

Answer:

Large crystals

Slowly

Explanation:

Recrystallization is a procedure used to purify an impure compound in a solvent. The concept used here is that the solubility of most of the solids increases with increase in temperature.

Recrystallization is also called as method of fractional crystallization.

After a recrystallization, a pure substance will ideally appear as a network of large crystals. If this is not the case, it may be worthwhile to reheat the flask and allow the contents to cool more slowly.

Answer:

C2H2

Explanation:

Mass of Carbon in CO2[tex]= (12/44) (20.31)[/tex] grams [tex]= 5.54[/tex] gram

Mass of hydrogen in H2O [tex]= (2/18)(4.26)[/tex] grams [tex]= 0.46[/tex] gram

We will calculate the % of C and H in the sample  

% C [tex]= (5.54/6) * 100 = 92[/tex]%

% H [tex]= (0.46/6)*100 = 7.7[/tex]%

Number of mole of C [tex]= 92/12 = 7.69[/tex]

Number of mole of H [tex]= 7.67/1 = 7.67[/tex]

Fractional share of  C [tex]= 7.69/7.67 = 1[/tex]

Fractional share of  H [tex]= 7.67/7.67 = 1[/tex]

Empirical Formula = CH

Empirical Mass [tex]= 12+1 = 13[/tex]

Molecular mass [tex]= 26[/tex]

Molecular Formula – CHn  

N [tex]= 26/13 = 2[/tex]

Molecular Formula = C2H2

Answer:

Substance B, boiling point of 105 °C

Explanation:

Non volatile substances have high boiling points