Given the reactions:

2 X(s) + 2 H2O() → 2 X+(aq) + 2 OH–(aq) + H2(g)
2 Y(s) + 2 H2O() → 2 Y+(aq) + 2 OH–(aq) + H2(g)

The unknowns, X and Y, are most likely

A) metallic elements in the same group
B) metallic elements in the same period
C) nonmetallic elements in the same group
D) nonmetallic elements in the same period

[tex]1.985 \times 10^{24} \text { atoms }[/tex] is the calculated number of atoms in 75.8 g of Na

Explanation:

In order to go from mass of sodium to atoms of sodium, we have to do two things:

Step 1:

To calculate the number of atoms in a Na sample, divide its weight in grams by the amu atomic mass from the periodic table

We know the Molar mass of Na = 22.989770 g / mole

Given weight of Na in grams = 75.8 g

        [tex]75.8 g \times \frac{1 \mathrm{mole}}{22.989770 \mathrm{g}}=3.297 \mathrm{mole}[/tex]

Step 2:

Multiply the obtained result by Avogadro's number ([tex]6.02 \times 10^{23}[/tex])

       [tex]3.297 \text { mole } \times \frac{6.02 \times 10^{23} \text { atoms }}{1 \text { mole }}=19.85 \times 10^{23} \text { atoms }=1.985 \times 10^{23} \text { atoms }[/tex]

Answer:

                     Molarity  =  5.52 mol.L⁻¹

Explanation:

             Molarity is the amount of solute dissolved per unit volume of solution. It is expressed as,

                         Molarity  =  Moles / Volume of Solution    ----- (1)

Data Given;

                  Mass  =  250.0 g

                  Volume  =  775 mL  =  0.775 L

First calculate Moles for given mass as,

                   Moles  =  Mass / M.mass

                   Moles  =  250.0 g / 58.44 g.mol⁻¹

                   Moles  =  4.277 mol

Now, putting value of Moles and Volume in eq. 1,

                        Molarity  =  4.277 mol ÷ 0.775 L

                        Molarity  =  5.52 mol.L⁻¹

To find the empirical formula of lactic acid, we calculate the moles of C, H, and O from the products of combustion and determine the simplest whole number ratio. The molecular formula is then found by establishing the integer multiple of the empirical formula that matches the given molar mass of lactic acid.

To determine the empirical formula of lactic acid from the given combustion data, we use the mass of products to find the quantity of each element in the original compound. Starting with carbon, 14.7 g of CO2 is produced from the combustion of lactic acid. Using the molar mass of CO2 (44 g/mol), we calculate that there are 0.334 moles of carbon in the 10.0 g of lactic acid.

For hydrogen, 6.00 g of water means there are 0.333 moles of water, which equates to 0.667 moles of hydrogen, since each water molecule contains two hydrogen atoms. Oxygen is a bit more complicated because it's part of both CO2 and H2O. After accounting for the oxygen in CO2 and H2O, we calculate the remainder to be part of the lactic acid. The molar ratios of C:H:O give us the empirical formula, which can be determined by dividing each mole quantity by the smallest amount to find the simplest whole number ratio.

Given a molar mass of 90 g/mol for lactic acid, we can use the empirical formula mass to determine the number of empirical units in the molecular formula. The molecular formula can be found by multiplying the empirical formula by an integer factor that converts the empirical formula mass to the actual molar mass.

Explanation::

Electrochemical cell

It is the cell that converts the chemical energy in to electric energy .The reaction staking place in it are spontaneous that is occur by itself .

In it the oxidation and reduction both occur .

The one with high electrode potential looses electrons that is it shows : oxidation

Th one with lower electrode potential gains electrons that is  it shows :Reduction .

In this galvanic cell (Zn-Cu couple )

The oxidation occurs at anode that is :

Zn-2e---->Zn²⁺

The reduction occurs at cathode :

Cu²⁺  + 2e--->Cu

Answer:

The correct answer is option B ;)

Explanation:

Answer: 1 mole Kr

Explanation: solution

83.80g Kr x 1mole Kr / 84 g Kr

= 0.997 or approximately 1 mole Kr

A rock with a striped pattern is classified as a metamorphic rock because its characteristics indicate that it has been transformed under high heat and pressure, realigning its mineral structure.

When classifying a rock with stripes, it suggests a transformation under high heat and pressure which typically results in the reorientation of minerals within the rock. This description fits the formation process of metamorphic rocks. Therefore, any rock with a striped pattern is likely a metamorphic rock, as igneous rocks form from the cooling of magma or lava and would not have stripes, and sedimentary rocks are characterized by layers formed from deposited sediment and can sometimes contain fossils.

Final answer:

The rock in question should be classified as metamorphic due to its striped look, which is a result of high heat and pressure reorienting minerals within the rock, characteristic of metamorphism.

Explanation:

You would classify this rock as metamorphic because it has a striped look, which is indicative of the foliation process that occurs when a pre-existing rock is transformed due to high heat and pressure. This reorientation of minerals within the rock often gives it a layered or striped appearance, a characteristic feature of metamorphic rocks. Sedimentary rocks, while they also have layers, are formed from particles of pre-existing rocks or organic material that have been compacted and cemented together.

These can sometimes contain fossils, but it is the presence of distinct stripes from the reorientation of minerals that suggests a metamorphic origin in the case you've mentioned. Igneous rocks with large crystals are formed from magma that solidifies slowly beneath the Earth's surface, but these do not have the striped appearance associated with metamorphic rocks.

Answer: Comparisons .

Answer:

c

Explanation:

the answer is comparisons

Answer:

Sodium (NA)

Explanation:

Answer:

rubidium: rb

Explanation:

Answer:

heterogeneous catalyst

Explanation:

The reaction equation:

                        MnO₂[tex]_{s}[/tex]

         H₂O₂[tex]_{l}[/tex]         →             2H₂[tex]_{g}[/tex]     +   2O₂[tex]_{g}[/tex]

A catalyst is any species that speeds up the rate of chemical reactions. It does not get used up in the reaction but helps facilitate the rate by which two species combines.

In this reaction, MnO₂ is the catalyst used in this reaction.

The catalyst still remains at the end of the reaction.

  Now, we know that from the subscript, the reactant is in liquid phase, the products are in gaseous phase and the catalyst is in solid phase.

A catalyst in a reaction in a different phase with the reactants is called a heterogeneous catalyst.

Answer:

The answer is B. A heterogeneous catalyst is being used in the reaction.

Explanation:

Answer: b. the total number of gas molecules will decrease.

Explanation:

According to principle, how will a pressure increase affect a system that includes matter in the gas phase and another phase that means the total number of gas molecules will decrease.

This principle shows that when we alter a system in equilibrium, it will seek to acquire a new state that cancels out this disturbance. Thus, there is a shift in equilibrium, that is, a search for a new equilibrium situation, favoring one of the reaction directions.

principle concerns the response of systems in equilibrium when subjected to a perturbation. Simply put, the principle says that a system in equilibrium when disturbed tends to adjust itself in order to remove the disturbance and restore equilibrium.

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Answer:

78.4L

Explanation:

1 mole of any gas is found to occupy 22.4L at stp. This also indicates that 1mole of oxygen occupy 22.4L.

Therefore,

3.50 moles of oxygen Will occupy = 3.5x22.4 = 78.4L

At Standard Temperature and Pressure (STP), one mole of an ideal gas occupies around 22.4 liters. Accordingly, 3.50 moles of oxygen would occupy a volume of 78.4 liters.

The question is inquiring about the volume an ideal gas, in this case oxygen, would occupy at Standard Temperature and Pressure (STP) given its quantity in moles. It's well established in chemistry that at STP, which is defined as a temperature of 273.15 K and a pressure of 1 atm, one mole of any ideal gas occupies approximately 22.4 liters. This is often known as the standard molar volume. Therefore, to calculate the volume that 3.50 moles of oxygen would occupy, multiply the number of moles (3.50) by the volume of one mole (22.4 L/mole) which results in a volume of 78.4 liters.

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Answer:

                     a)  2.53 × 10²³ molecules of O₂

                     b)  31.90 g of KCl

Explanation:

                  The balance chemical equation for given decomposition reaction is as follow;

                                   2 KClO₃ → 2 KCl + 3 O₂

Step 1: Calculate Moles for given amount of KClO₃;

                    Moles  =  Mass / M.Mass

                    Moles  =  34.35 g / 122.55 g/mol

                    Moles  =  0.280 moles of KClO₃

Step 2: Find out  moles of O₂ produced;

According to eq,

                  2 moles of KClO₃ produces  =  3 moles of O₂

So,

            0.280 moles of KClO₃ will produce  =  X moles of O₂

Solving for X,

                    X  =  0.280 mol × 3 mol / 2 mol

                     X =  0.42 moles of O₂

Step 3: Calculate No. of Molecules of O₂ as,

No. of Molecules  =  Moles × 6.022 × 10²³

No. of Molecules  =  0.42 mol × 6.022 × 10²³ molecules/mol

No. of Molecules  =  2.53 × 10²³ molecules of O₂

Step 1: Calculate Moles for given amount of KClO₃;

                    Moles  =  Mass / M.Mass

                    Moles  =  52.53 g / 122.55 g/mol

                    Moles  =  0.428 moles of KClO₃

Step 2: Find out  moles of KCl produced;

According to eq,

                  2 moles of KClO₃ produces  =  2 moles of KCl

So,

            0.428 moles of KClO₃ will produce  =  X moles of KCl

Solving for X,

                    X  =  0.428 mol × 2 mol / 2 mol

                     X =  0.428 moles of KCl

Step 3: Calculate Mass of KCl as;

                         Mass  =  Moles × M.Mass

                         Mass  =  0.428 mol × 74.55 g/mol

                         Mass  =  31.90 g of KCl

By calculating the number of moles of KClO3 and using the stoichiometric ratios in the balanced equation, we find that 34.35 grams of KClO3 will produce about 2.53 x 10^23 molecules of O2, and that 52.53 grams of KClO3 will form about 31.97 grams of KCl.

The first thing we should do is calculate the molar mass of KClO3 which is approximately 122.55 g/mol. Then, find the number of moles of KClO3 in each part of the question.

a. The number of moles in 34.35 grams of KClO3 is 34.35 g / 122.55 g/mol = 0.2803 mol. From our balanced equation we know we get 3 molecules of O2 for every 2 molecules of KClO3, so we get 0.2803 mol x (3/2) = 0.4205 mol of O2. In molecules, this is 0.4205 mol x Avogadro's number (6.022 x 10^23) = 2.53 x 10^23 molecules of O2.

b. For 52.53 grams of KClO3 we get a number of moles equal to 52.53 g / 122.55 g/mol = 0.4288 mol. Following the balanced equation, we get an equal amount of KCl, thus 0.4288 mol. In grams, this is 0.4288 mol x 74.55 g/mol (molar mass of KCl) = 31.97 grams of KCl.

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Answer:

[tex]\frac{[SO3][NO]}{[SO2][NO2]}[/tex]

Option D is the right answer.

Explanation:

When the rate of the forward reaction equals the rate of the reverse reaction, the chemical reaction is in equilibrium. The equilibrium constant (Kc) is used to determine whether reaction is in the equilibrium or not.

Example:

aA+bB⇋cC+dD      

Equilibrium constant (Kc)  for this reaction will be

Kc = [tex]\frac{[C]^c [D]^d}{[A]^a [B]^b}[/tex]

In this equation, [A] and [B] are equilibrium reactant concentrations. [C] and [D] are equilibrium product concentration and a, b, c, and d are the stoichiometric coefficients of the balanced reaction.

In our reaction,

SO2(g) + NO2(g) = S03(g) + NO(g)

Kc or Keq will be

Keq = [tex]\frac{[SO3][NO]}{[SO2][NO2]}[/tex]

This equation is balanced without any stoichiometric coefficients.

​

Answer:

                   Option-A (XY)

Explanation:

                    In this problem one should focus on the number of valence electrons present in each atom. Remember that in lewis structure the dots on an atom always show the valence shell electrons. In given statement;

The,

                   X has one valence electron. It means that it can loose this single electron to attain the noble gas configuration i.e.

                                          X°  →  X⁺  +  1e⁻

Similarly,

                 Y have seven valence shell electrons. Therefore, in order to complete the octet this atom will gain one electron i.e.

                                          ::Y:°  +  1 e⁻  →  Y⁻

Hence, we can conclude that X got stabilized by losing one electron and Y got stabilized by gaining one electron therefore, only one of each is required to form an ionic compound i.e.

B.

Both use kinetic energy to produce electricity is a similarity between power plants that use water as an energy source and those that use wind as an energy source.

Explanation:

Kinetic energy Is the intrinsic energy that an object or substance possesses due to its motion. All power plants that use water as an energy source utilize the kinetic energy of water to produce electricity. For example, hydro-power plants use the kinetic energy of water flowing due to gravity. Tidal power plants utilize the kinetic energy of water flowing due to tidal changes and geothermal powerplants utilize the energy of steam-water ejecting underground through fissures.

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Answer:                  34.0147 g/mol

Explanation:

Answer:34.02g/mol

Explanation:H2O2

2x1.01 + 2x16 grams/mols

2.02 + 32 =34 .2g/mol

Answer:

Because there is a lesser if not absent atmospheric pressure on Mars relative to earth

Explanation:

On earth the liquid water will experience atmospheric downward pressure due to the earth's atmosphere which will require it to evaporate at a vapour pressure that is greater than the atmospheric pressure. This is not the case for Mars which lacks an atmosphere due to its weak gravitional pull, water will therefore evaporate easily on mars than on earth

Answer:

C D A B

Explanation:

Final answer:

The reaction is a decomposition reaction where sodium azide decomposes into sodium and nitrogen gas.

Explanation:

The type of reaction represented is a decomposition reaction. This is a chemical reaction where a single compound breaks down into two or more elements or simpler compounds. Sodium azide (NaN3) decomposes into sodium metal (Na) and nitrogen gas (N2). One mole of sodium azide (NaN3) has a molar mass of approximately 65 g/mol.

Therefore, if 23.4 g of sodium azide is used, the moles of nitrogen gas produced can be calculated using the molar mass and the stoichiometry of the reaction. At standard temperature and pressure (STP), one mole of any gas occupies approximately 22.4 liters. By using the stoichiometry of the balanced equation, one can determine the volume of nitrogen gas produced at STP from a given amount of sodium azide.

Answer:

yes it doese

Explanation:

Answer:

a

Explanation:

Answer:

a

Explanation:

Answer:

Potential

Explanation:

The higher the elevation is the higher the potential energy levels are also the ball is not moving so it is not using kinetic energy.

Answer:

2K + HgCl2 —> Hg + 2KCl

Explanation:

K + HgCl2 —> Hg + KCl

The above equation is not balanced

To balance the equation, do the following.

First, put 2 in front of KCl, the equation becomes,

K + HgCl2 —> Hg + 2KCl

Now we see that Cl is balanced but K is not. To balance K, put 2 in front of K as shown below:

2K + HgCl2 —> Hg + 2KCl

Now we can that the equation is balanced

Answer:

its to hard

Explanation:

Answer:

its to hard

Explanation:

Answer:

D = All of these

Explanation:

Physical properties:

Physical properties involve those properties which includes the state of matter.

For example,

Melting point, boiling point, freezing point, density, smell, color

In given example,

The density of gold is 19.32 g/mL

Melting point is 1064.58°C

Boiling point is 2807°C

All these are physical properties.

Chemical properties:

Chemical properties includes those properties which involves the chemical reaction

For example.

Flammability, reactivity, acidity, heat of combustion, toxicity etc.

The reaction of gold with oxygen:

Chemical equation,

3Au + O₂  →  Au₂O₃

Answer:

that light is on the electromagnetic spectrum

Explanation:

this is because In physics, the term light sometimes refers to electromagnetic radiation of any wavelength, whether visible or not. In this sense, gamma rays, X-rays, microwaves and radio waves are also light. Like all types of EM radiation, visible light propagates as waves. However, the energy imparted by the waves is absorbed at single locations the way particles are absorbed. The absorbed energy of the EM waves is called a photon, and represents the quanta of light.

Answer:

light is made of particles, called photons. Except their movement to earth, every photon vibrates in every direction (they vibrate in just one direction if light is polarized).

Explanation:

Final answer:

The area of a rectangular field measuring 6.0 m by 8.0 m is 480,000 cm², which is 4.8 × 10⁵ cm² in scientific notation. So the correct option is B.

Explanation:

To calculate the area of a rectangular field in square centimeters, you would use the formula Area = length × width. First, we must ensure that both dimensions are in the same units, so we convert the dimensions from meters to centimeters. There are 100 centimeters in a meter, so:

Next, we calculate the area using the converted measurements:

Area = 600 cm × 800 cm = 480,000 cm²

Therefore, the area of the field in square centimeters is 480,000 cm², which can be expressed in scientific notation as 4.8 × 105 cm2, making option B the correct answer.

The density of the unknown liquid is calculated by subtracting the weight of the empty beaker from the weight of the beaker with the liquid to obtain the weight of the liquid. This is then divided by the volume of the liquid (given as 10ml) to calculate the density, which is 0.77568 g/ml.

The subject of this question is density, a concept in chemistry frequently utilized in high school. To calculate the density of the unknown liquid, we subtract the weight of the empty beaker from the weight of the beaker with the liquid. This gives us the weight of the liquid alone, which equals 40.1825 grams - 32.4257 grams = 7.7568 grams. The volume of the liquid is given as 10 ml. Hence, the density (D) is calculated by dividing the mass (M) of the substance by its volume (V), i.e., D = M / V = 7.7568 grams / 10 ml = 0.77568 g/ml.

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