Question 9 of 10
Which statement correctly describes magnetic field lines?
O A. They cross each other at right angles.
B. They always point away from a south pole.
C. They show the direction a south pole will point.
D. They join north pole to south pole..

Explanation:

elements are carbons and hydrogen

Answer:

Carbon and Hydrogen.

Explanation:

It’s in the name Hydro (H) Carbon (C)

Answer:

This question is incomplete

Explanation:

This question is incomplete but the completed question is below;

"The following list of properties is most descriptive of a(n) ______

1. High melting point, conductor of electricity when dissolved in water

2. Low melting point, non-conductor of electric current

3. Malleable, ductile, insoluble in water.

The choices for all 3 are: a) metallic solid b) molecular solid c) ionic solid d) all of these e) none of these f) more than one of these"

1. Ionic solid: Ionic solids are solids that have ionic/electrovalent bonds holding it's constituent molecules together. These bonds are strong bonds that involve the transfer of electrons from one constituent atom (the metal) to another constituent atom (the nonmetal). This strong bond causes the solid to have a high melting and boiling point. Also, when dissolved in water, the constituent atoms (involved in the electron transfer) dissociate to form ions (become charged) and thus easily carry electric charges (i.e conduct electricity).

Examples are Sodium Chloride and Potassium Iodide

2. Molecular solids: These are solids whose constituent molecules are held together by a weak bond/force known as Van der Waal forces. This forces are easily broken down when subjected to heat and thus the molecular solids have a low melting point. Also, these solids do not have carriers of heat or electric charges in them and are thus non-conductors of electric current.

Examples are Ice (frozen water) and sucrose

3. Metallic solids: These of solids made from constituent metal atoms only. The nuclei of these constituent metal atoms have the ability to move past one another without disrupting there metallic bonding; it is for this reason they are malleable and ductile. There constituent atoms however do not dissociate in water and are thus insoluble in water.

Examples are aluminium and copper crystal.

Answer:

The volume will be 185.83 mL.

Explanation:

Gay-Lussac's law indicates that when there is a constant volume, as the temperature increases, the pressure of the gas increases. And when the temperature is decreased, the pressure of the gas decreases. Gay-Lussac's law can be expressed mathematically as follows:

[tex]\frac{P}{T} =k[/tex]

Where P = pressure, T = temperature, k = Constant

Boyle's law says that the volume occupied by a given gaseous mass at constant temperature is inversely proportional to pressure. Boyle's law is expressed mathematically as:

P*V=k

Where P = pressure, V = volume, k = Constant

Finally, Charles's Law consists of the relationship that exists between the volume and the temperature of a certain quantity of ideal gas, which is kept at a constant pressure. For a given sum of gas at a constant pressure, as the temperature increases, the volume of the gas increases and as the temperature decreases, the volume of the gas decreases because the temperature is directly related to the energy of the movement of the gas molecules. .

In summary, Charles's law is a law that says that when the amount of gas and pressure are kept constant, the quotient that exists between the volume and the temperature will always have the same value:

[tex]\frac{V}{T} =k[/tex]

Combined law equation is the combination of three gas laws called Boyle's, Charlie's and Gay-Lusac's law:

[tex]\frac{P*V}{T} =k[/tex]

Studying two different states, an initial state 1 and a final state 2, it is satisfied:

[tex]\frac{P1*V1}{T1} =\frac{P2*V2}{T2}[/tex]

In this case:

Replacing:

[tex]\frac{720 torr*256 mL}{308 K} =\frac{950 torr*V2}{295 K}[/tex]

Solving:

[tex]V2= \frac{295K}{950 torr} *\frac{720 torr*256 mL}{308 K}[/tex]

V2= 185.83 mL

The volume will be 185.83 mL.

Answer:

C

Explanation:

The specific heat capacity=quantity of heat in joule/mass×change in temperature

from this question the quantity of heat is 75250,the mass is 2000 and the change in temperature is 50-30

which is 20

therefore

c=75250/2000×20

c=75250/40000

c=1.88

I hope this helps

Answer:

a. True

Explanation:

There is strong inhibition of Carbon Anhydrase by Aceta-zolamide Carbonic Anhydrase. The drug acetazolamide is used as diuretic which increase the urine production in human body. It lowers pressure in eye in glaucoma.

Answer:

a. 599 cm³

b. 1.49 g/cm³

Explanation:

Volume is the amount of space an object occupies. Since this is a brick, the object is a rectangular prism. The formula for the volume of a rectangular prism is the product of length, width, and height.

[tex]V= l *w*h[/tex]

The brick's length (l) is 13.77 centimeters, the width (w) is 8.50 centimeters, and the height (h) is 5.12 centimeters. Substitute these values into the formula.

[tex]V= 13.77 \ cm * 8.50 \ cm * 5.12 \ cm[/tex]

Multiply the numbers together.

[tex]V= 117.045 \ cm^ 2* 5.12 \ cm[/tex]

[tex]V= 599.2704 \ cm^3[/tex]

The original measurements have at least 3 significant figures, so our answer must have 3. For the number we calculated, that is the ones place. The 2 in the tenths place tells us to leave the 9 in the ones place.

[tex]V \approx 599 \ cm^3[/tex]

[tex]\bold {The \ volume \ of \ the \ brick \ is \ approximately \ 599 \ cubic \ centimeters}}[/tex]

Density is the amount of matter in a specified space. The formula for density is mass over volume.

[tex]d= \frac{m}{v}[/tex]

The mass of the brick is 895.3 grams and we just found the volume to be 599.2704 cubic centimeters. Substitute the values into the formula.

[tex]d= \frac{895.3 \ g}{599 \ cm^3}[/tex]

Divide.

[tex]d= 1.494657763 \ g/cm^3[/tex]

Round to three significant figures. For the number we calculated, that is the hundredth place. The 4 in the thousandth place tells us to leave the 9 in the hundredth place.

[tex]d \approx 1.49 \ g/cm^3[/tex]

[tex]\bold {The \ density\ of \ the \ brick \ is \ approximately \ 1.49 \ grams /cubic \ centimeters}}[/tex]

Solution :

Spontaneous Process

A spontaneous process is defined as the process that occurs without the help of any external aid or inputs. A spontaneous process is a natural process which occurs naturally in the environment.

Non Spontaneous process

A non spontaneous process is a process which does not occur naturally. Some inputs are provided for the process to occur. Energy from external source is applied into the process to start the process.

The following processes are :

1. Melling of ice   ---- Spontaneous

2 Rusting of iron  --- Spontaneous

3. Marble going down the spiral.   --- spontaneous

4. Going up the hill  ---- Non spontaneous

5. Keeping the food fresh from spoilage​  --- Non spontaneous

Answer:

[tex]\boxed {\boxed {\sf 8.10 \ L}}[/tex]

Explanation:

This question asks us find the volume of a gas sample given a change in temperature. Since the pressure remains constant, we only are concerned with the variables of temperature and volume.

We will use Charles's Law. This states the volume of a gas is directly proportional to the temperature of a gas. The formula is:

[tex]\frac{V_1}{T_1}=\frac{V_2}{T_2}[/tex]

The gas starts at a volume of 2.70 liters and a temperature of 25.0 degrees Celsius.

[tex]\frac {2.70 \ L}{25.0 \textdegree C}=\frac{V_2}{T_2}[/tex]

The temperature is increased to 75.0 degrees Celsius, but the volume is unknown.

[tex]\frac {2.70 \ L}{25.0 \textdegree C}=\frac{V_2}{75.0 \textdegree C}[/tex]

We are solving for the volume at 75 degrees Celsius, so we must isolate the variable V₂.

It is being divided by 75.0 °C. The inverse operation of division is multiplication, so we multiply both sides of the equation by 75.0 °C.

[tex]75.0 \textdegree C *\frac {2.70 \ L}{25.0 \textdegree C}=\frac{V_2}{75.0 \textdegree C} * 75.0 \textdegree C[/tex]

[tex]75.0 \textdegree C *\frac {2.70 \ L}{25.0 \textdegree C}= V_2[/tex]

The units of degrees Celsius (° C) cancel.

[tex]75.0 *\frac {2.70 \ L}{25.0}= V_2[/tex]

[tex]75.0 *0.108 \ L = V_2[/tex]

[tex]8.1 \ L = V_2[/tex]

The original measurements have 3 significant figures, so our answer must have the same. Currently, the answer has 2. If we add another 0, the value of the answer does not change, but the number of sig figs does.

[tex]8.10 \ L = V_2[/tex]

The volume of this gas sample at 75.0 degrees Celsius is 8.10 Liters.

Answer:

0.030 M

Explanation:

Step 1: Make an ICE chart

        2 SO₂(g) + O₂(g) ⇄ 2 SO₃(g)

I        0.060      0.050          0

C         -2x            -x            +2x

E     0.060-2x  0.050-x       2x

Step 2: Find the value of x

The concentration of SO₃ at equilibrium is 0.040 mol/L. Then,

2x = 0.040

x = 0.020

Step 3: Calculate the concentration at equilibrium of O₂

[O₂] = 0.050 - x = 0.050 - 0.020 = 0.030 M

The equilibrium concentration of oxygen is 0.030 M.

A reversible reaction is a reaction that can move either in the forward or in the reverse direction. We have the reaction; 2SO2(g) + O2(g) ⇄ 2SO3(g). We can now set up the ICE table as shown below;

  2 SO₂(g) + O₂(g) ⇄ 2 SO₃(g)

I        0.060      0.050          0

C         -2x            -x            +2x

E     0.060-2x  0.050-x       2x

At equilibrium;

2x = 0.040 M

x = 0.040 M/2 =  0.020 M

For oxygen;

0.050-x  

0.050 M - 0.020 M = 0.030 M

Learn more about equilibrium: https://brainly.com/question/953809

Answer:

Formic acid

Sodium formiate

Explanation:

To determine acid or base that can generate a buffer solution with pH around 3.5, we have to think in the acid whose pKa = pH.

Although we have to also think in buffer capacity, a measure which can cause a change of 1 pH unit in 1 L of solution.

Buffer capacity does not only depend on the concentration of its components but also of the relationship between that concentrations.

When pH = pKa, buffer capacity is maximum which means that the concentration of conjugated species is the same and the ability to oppose pH changes is maximum.

One example with pH = pKa or nearly if:

COOH⁻  + Na⁺ →  NaCOOH

HCOOH  +  H₂O  →  COOH⁻  + H₃O⁺     Ka: 1.8×10⁻⁴

pKa = 3.74

Answer:

1860g.

Explanation:

It is known that the molar mass of C2H6O2 is 62.08 g/mol.,

Now to  solve for the number of moles of solute, one must multiply both

sides by the volume:

moles of solute = (6.00 M)(5.00 L) = 30.0 mol

Notice since the definition of molarity is mol/L, the

product M × L gives mol, a unit of amount.

Use the molar  mass of C3H8O3, one can convert mol to g:

Mass m =30 mol × 62.08 g/mol

m = 1860g.

Hence, there are 1,860 g of C2H6O2 in the specified amount of

engine coolant.

Answer:

0.93 M

Step-by-step Explanation:

First, we have to calculate the molar mass (MM) of ZnSO₄ by using the molar mass of each chemical element:

MM(ZnSO₄) = 65.4 g/mol Zn + 32 g/mol S + (16 g/mol x 4) = 161.4 g/mol

Then, we divide the mass of ZnSO₄ into its molar mass to obtain the number of moles:

moles ZnSO₄ = mass/MM = 150 g/(161.4 g/mol)= 0.93 mol

Since the molarity of a solution expresses the number of moles of solute per liter of solution, we calculate the molarity (M) as follows:

M = moles ZnSO₄/1 L =  0.93 mol/1 L = 0.93 M

Answer:

123456788012346778901234567890

Answer:

Mass=Moles × RFM

Mass= 0.28M× 164

Mass= 45.92 grammes

Answer:

The correct equation is "[tex]\frac{[Ni(H_2O)_3 (NH_3)]^{2+}}{[Ni(H_2O)_4]^{2+} [NH_3]}[/tex]".

Explanation:

According to the question,

Throughout an aqueous solution, [tex]Ni^{2+}[/tex] exist as [tex][Ni(H_2O)_4]^{2+}[/tex]

So,

⇒ [tex][Ni(H_2O)_4]^{2+} + 4NH_3 \rightleftharpoons [Ni(NH_3)_4]^{2+} + H_2O[/tex]

⇒ [tex]K_f = \frac{[Ni(NH_3)_4]^{2+}}{[Ni(H_2O)_4^{2+}] [NH_3]^4}[/tex]

Here, we have excluded [tex][H_2O][/tex] as concentration of water will be const.

Now,

This formation of [tex][Ni(NH_3)_4]^{2+}[/tex] proceeds via several steps,

Step 1:

⇒ [tex][Ni(H_2O)_4]^{2+}+NH_3 \rightleftharpoons [Ni(H_2O)_3 (NH_3)]^{2+} + H_2O[/tex]

⇒ [tex]K_1 = \frac{[Ni(H_2O)_3 (NH_3)]^{2+}}{[Ni(H_2O)_4]^{2+} [NH_3]}[/tex]

Ribose is a reducing sugar. A reducing sugar is a carbohydrate that can undergo a redox reaction, in which it donates electrons to another chemical species.

This is usually observed when the sugar opens its ring structure to form an aldehyde or ketone functional group.

Ribose, a five-carbon sugar, can form an open-chain structure with an aldehyde functional group. In this form, it can donate electrons and act as a reducing agent in certain chemical reactions, such as the reduction of other compounds like Benedict's reagent during laboratory tests for reducing sugars.

Learn more about Ribose, here:

https://brainly.com/question/34709209

#SPJ6

Answer:

NON-METAL

Explanation:

Phosphorus is a non-metal that sits just below nitrogen in group 15 of the periodic table. This element exists in several forms, of which white and red are the best known.

Answer:.......

Explanation:

Answer:

56.9 mmoles of acetate are required in this buffer

Explanation:

To solve this, we can think in the Henderson Hasselbach equation:

pH = pKa + log ([CH₃COO⁻] / [CH₃COOH])

To make the buffer we know:

CH₃COOH  +  H₂O  ⇄   CH₃COO⁻  +  H₃O⁺     Ka

We know that Ka from acetic acid is: 1.8×10⁻⁵

pKa = - log Ka

pKa = 4.74

We replace data:

5.5 = 4.74 + log ([acetate] / 10 mmol)

5.5 - 4.74 = log ([acetate] / 10 mmol)

0.755 = log ([acetate] / 10 mmol)

10⁰'⁷⁵⁵ = ([acetate] / 10 mmol)

5.69 = ([acetate] / 10 mmol)

5.69 . 10 = [acetate] → 56.9 mmoles

Answer:

the number of protons in a atom is unique to each element

Explanation:

protons are about 99.86% as massive neutrons. The number of protons in a atom is unique to each element .For example carbon atoms have six protons in an atom is referred to as the atomic number of that element

Answer:

2 H₂O(l) + 2 e⁻ ⇒ H₂(g) + 2 OH⁻(aq)

Explanation:

Let's consider the unbalanced half-reaction for the reduction of liquid water to gaseous hydrogen in basic aqueous solution.

H₂O(l) ⇒ H₂(g)

First, we will perform the mass balance. We will balance oxygen atoms by multiplying H₂O by 2 and adding 2 OH⁻ to the right side.

2 H₂O(l) ⇒ H₂(g) + 2 OH⁻(aq)

Then, we perform the charge balance by adding 2 electrons to the left side.

2 H₂O(l) + 2 e⁻ ⇒ H₂(g) + 2 OH⁻(aq)

Answer:

Temperature affects the kinetic energy in a gas the most, followed by a comparable liquid, and then a comparable solid. The higher the temperature, the higher the average kinetic energy, but the magnitude of this difference depends on the amount of motion intrinsically present within these phases.

Explanation:

Liquids have more kinetic energy than solids. When a substance increases in temperature, heat is being added, and its particles are gaining kinetic energy. Because of their close proximity to one another, liquid and solid particles experience intermolecular forces. These forces keep particles close together.

Answer:

a. discrete analyzer

b. 96 well microplate

c. flow injection analysis

d. colorimeter

Explanation:

96 well microplates are instruments designed for sample collection and throughput screening. If an environment lab has collected 2000 samples then 96 well microplate is best suited application. Discrete analyzer is automated chemical analyzer which performs test on samples kept in discrete cells. Flow injection analysis is approach used for chemical analysis. It injects a plug of sample into a flowing carrier stream. Colorimeter is a device which measures absorbance of wavelength of light by a specific solution.

Answer:

0.21 g

Explanation:

The equation of the reaction is;

NaCl(aq) + AgNO3(aq) -----> NaNO3(aq) + AgCl(s)

Number of moles of NaCl= 0.0860 g /58.5 g/mol = 0.00147 moles

Number of moles of AgNO3 = 30/1000 L × 0.050 M = 0.0015 moles

Since the reaction is 1:1, NaCl is the limiting reactant.

1 mole of NaCl yields 1 mole of AgCl

0.00147 moles of NaCl yields 0.00147 moles of AgCl

Mass of precipitate formed = 0.00147 moles of AgCl × 143.32 g/mol

= 0.21 g

Answer: The boiling point of the solution is [tex]101.02^oC[/tex]

Explanation:

We are given:

3.5 % (by weight) NaCl

This means that 3.5 g of NaCl is present in 100 g of solution

Mass of solvent = Mass of solution - Mass of solute

Mass of solvent (water) = (100 - 3.5) g = 96.5 g

Elevation in the boiling point is defined as the difference between the boiling point of the solution and the boiling point of the pure solvent.

The expression for the calculation of elevation in boiling point is:

[tex]\text{Boiling point of solution}-\text{boiling point of pure solvent}=i\times K_b\times m[/tex]

OR

[tex]\text{Boiling point of solution}-\text{Boiling point of pure solvent}=i\times K_f\times \frac{m_{solute}\times 1000}{M_{solute}\times w_{solvent}\text{(in g)}}[/tex] ......(1)

where,

Boiling point of pure solvent (water) = [tex]100^oC[/tex]

Boiling point of solution = ?

i = Vant Hoff factor = 2 (for NaCl)

[tex]K_b[/tex] = Boiling point elevation constant = [tex]0.512^oC/m[/tex]

[tex]m_{solute}[/tex] = Given mass of solute (NaCl) = 3.5 g

[tex]M_{solute}[/tex] = Molar mass of solute (NaCl) = 36.5 g/mol

[tex]w_{solvent}[/tex] = Mass of solvent (water) = 96.5 g

Putting values in equation 1, we get:

[tex]\text{Boiling point of solution}-(100)=2\times 0.512\times \frac{3.5\times 1000}{36.5\times 96.5}\\\\\text{Boiling point of solution}=(1.02+100)^oC\\\\\text{Boiling point of solution}=101.02^oC[/tex]

Hence, the boiling point of the solution is [tex]101.02^oC[/tex]

Explanation:

since there are no lone pairs on the central atom, the shape will be tetrahedral

Answer:

a. 0.7119 g

Explanation:

To solve this question we need to know that all carbon of the compound will react producing CO2 and all Hydrogen producing H2O.

Thus, we can find the mass of C and the mass of H and by difference regard to the 2.584g of the compound we can find the mass of oxygen as follows:

Moles CO2 = Moles C -Molar mass: 44.01g/mol-

5.874g CO2 * (1mol/44.01g) = 0.1335 moles CO2 = 0.1335 moles C

Mass C -Molar mass: 12.01g/mol-:

0.1335 moles C * (12.01g /mol) = 1.6030g C

Moles H2O -Molar mass: 18.01g/mol-

2.404gH2O * (1mol / 18.01g) = 0.1335 moles H2O * (2mol H / 1mol H2O) = 0.267 moles H

Mass H -Molar mass: 1g/mol-

0.267 moles H * (1g/mol) = 0.2670g H

Mass Oxygen =

Mass O = 2.584g compound - 1.6030g C - 0.2670g H

Mass O = 0.714g O ≈

Answer:

i dont know mate

Explanation: