A sample of uranium absorbs 27.16 kJ of energy and changes temperature by 347.6 C. If 27.17 J/(1C * 1 mole) for uranium, the how many mole of U are in the sample?

Answer:

No. Although alkali metals and alkaline earth metals are found in nature, they  are not found as pure elements. Group 1 and 2 are found in their chemical compounds, not pure form.

Answer:

54.75 mL

Explanation:

First calculate the number of moles of NaCl in the 150mL solution of NaCl

0.0365 moles should be present on 1000cm3 or 1dm3 of water.

1L = 1 dm3

1 mL = 1 / 1000 dm3

150 mL = 150/1000 dm3 = 0.15 dm3

If x moles are present in 0.15 dm3,

x/ 0.15 = 0.0365

We get x= 0.0365 × 0.15 mol

Now x amount of moles should be taken from the initial 0.100 M NaCl solution

So 0.1 moldm-3 = 0.0365× 0.15 mol / V

we get V = 0.05475 dm3

V= 0.05475 L

V= 54.75 mL

Answer:

The highlighted words in the explanation.

Explanation:

A clue comes by considering the noble gas elements, the rightmost column of the periodic table. These elements—helium, neon, argon, krypton, xenon, and radon—do not form compounds very easily, which suggests that they are especially stable as lone atoms. What else do the noble gas elements have in common?

Answer:

40

Explanation:

The total mass of calcium in the products is 40

The mass number (represented by the letter A) is defined as the total number of protons and neutrons in an atom. Consider the table below, which shows data from the first six elements of the periodic table. Consider the element helium. Its atomic number is 2, so it has two protons in its nucleus.

Together, the number of protons and the number of neutrons determine an element's mass number: mass number = protons + neutrons. If you want to calculate how many neutrons an atom has, you can simply subtract the number of protons, or atomic number, from the mass number.

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Answer:

CaCl2

CaO

Al2O3

AlCl3

You can do this by swapping the values of charges on the ions as below

eg- Ca2+ - 2

Cl- - 1

Now combine 1 Ca atom and 2 Cl atoms and it will give you CaCl2

Al 3+ - 3

O2- - 2

Combine 2 atoms of Al and 3 atoms of O

Al2O3

In the case of CaO, we have to make sure that the atoms are in their simplest ratio. So although we get Ca2O2, CaO is the correct form

Answer:

a chemical compound

Explanation:

copper(ii) chlorate is a chemical compound of the transition metal copper and the chlorate anion with basic formula cu(cio)3 and 2

helium is in group 8 and period 1

Answer:

25.1 moles

Hence it can be seen that when 25.1 moles of carbon dioxide gas react with excess hydrogen gas, 25.1 moles of methane gas are produced.

Answer:

Transpiration is the correct answer mark me brainliest

Answer:

Cl < P < Mg < Na

Explanation:

Cl must have the smallest radius because it is located to the right of the remaining elements on the same row. P  must have the second smallest radius because it is located to the right of the remaining elements on the same  row. Mg must have the Third smallest radius because it is located to the right of Na on the same row.  Therefore, Na has the Largest radius.

I hope it helps.

Taking into account the reaction stoichiometry and the definition of molar mass, the quantity of HgO used is 0.01385 moles and 0.006925 moles of O₂ are formed when 3.00 grams of HgO was used.

In first place, the balanced reaction is:

2 HgO → 2 Hg + O₂

By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:

The molar mass of the compounds is:

You know that 3.00 grams of HgO was used. Then, the quantity in moles of HgO used, can be calculated using the molar mass of HgO as follow:

[tex]3 gramsx\frac{1 mole}{216.59 grams}[/tex]=  0.01385 moles

Finally, the quantity of HgO used is 0.01385 moles.

To determine the number of moles of oxygen gas formed, the following rule of three can be applied: if by reaction stoichiometry 2 moles of HgO form 1 mole of O₂, 0.01385 moles of HgO form how many moles of O₂?

[tex]amount of moles of O_{2} =\frac{0.01385 moles of HgOx1 mole of O_{2} }{2 moles of HgO}[/tex]

amount of moles of O₂= 0.006925 moles

Then, 0.006925 moles of O₂ are formed when 3.00 grams of HgO was used.

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Answer:

d an attraction between positive ions and electrons

This problem provides information about the decomposition of copper(II) nitrate to copper(II) oxide and dinitrogen monoxide; for example, it is endothermic, the enthalpies of formation and the chemical reaction, as well as copper (II) sulfate which when dissolved in water, exhibits a temperature decrease:

[tex]2Cu(NO_3)_2(s) \rightarrow 2CuO(s) + 4NO_2(g) + O_2(g)[/tex]

First of all, we can draw the reaction pathway as shown on the attached figure, by taking into account the positive enthalpy change as it is endothermic, so that the products turn out with higher energy than the reactants, for it to be positive. In addition, keep in mind that top point is the activation energy the reaction needs to take place.

Next, we calculate the enthalpy change for this reaction by using the general formula which subtracts the enthalpy of formation of products and reactants with each species' correct stoichiometric coefficient:

[tex]\Delta H=2\Delta _fH_{CuO}+4\Delta _fH_{NO_2}+\Delta _fH_{O_2}-2\Delta _fH_{Cu(NO_3)_2}[/tex]

So we plug in the given enthalpies of formation:

[tex]\Delta H=2(-157.3)+4(33.2)+(0)-2(-302.9)=424.0 kJ/mol[/tex]

Finally, we go over the calorimetry experiment, whereby the total heat absorbed by the copper(II) sulfate is calculated via the general heat equation, which includes the heat loss from the solution of water and the salt:

[tex]Q_{rxn}=-mC_w\Delta T\\\\Q_{rxn}=-(100+25)g*4.18\frac{J}{g\°C}*-2.9\°C=1515.25J[/tex]

By dividing the previous answer by the moles of salt:

[tex]n=25.0g*\frac{1mol}{249.7g}=0.100mol[/tex]

We can obtain the enthalpy change of solution of the copper salt:

[tex]\Delta _{dissolution}H=\frac{1,515.25J}{0.100mol} \\\\\Delta _{dissolution}H=15,134J/mol=15.1kJ/mol[/tex]

To conclude, it is important to note that one possible source of error is we are assuming the solution has the same specific heat to that of water and that is not necessarily true. Also, we are neglecting any heat transfer to and from the surroundings despite the polystyrene beaker is considered a heat isolator, which means the results cannot necesarilly be accurate and the enthalpy change could have turned out higher or lower in a rigoruous experiment.

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Answer:

Oxide sugar dissolved in water pond

because water + sugar= sugar melts but the oxide purifys the water.

Explanation:

#carryonlearning!

Answer:

1) 1.39 * 10²³ atoms

Explanation:

Answer:

???

Explanation:

I have no clue sorry

Answer:

the water in the mountains will take longer to boil, because of the higher atmospheric pressu

Answer:

the ocean, the ocean floor basalts, evaporite deposits and reduced marine sediments.

Explanation:

Rusting is an electrochemical reaction. Iron rusts faster when alloyed with cobalt than when alloyed with manganese because, in the iron-manganese alloy, manganese is rendered the anode and iron is rendered the cathode

An alloy is a combination of two metals. There are various reasons for producing alloys such as greater tensile strength, corrosion resistance and improved aesthetic appearance.

When iron is alloyed with cobalt, the iron rusts faster than pure iron because iron is rendered the anode and cobalt is rendered the cathode. When the iron is alloyed with manganese, it rusts more slowly than pure iron because in the iron-manganese alloy, manganese is rendered the anode and iron is rendered the cathode.

Missing parts;

An iron object alloyed with cobalt rusts more quickly than a pure iron object. However, an iron object alloyed with manganese rusts less quickly than a pure iron object under the same conditions. This is true because

(1) cobalt is a stronger reducing agent than iron

(2) iron is a stronger reducing agent than manganese

(3) cobalt exhibits more metallic character than either iron or manganese

(4) in the iron-manganese alloy, manganese is rendered the anode and iron is rendered the cathode

(5) in the iron-cobalt alloy, cobalt is rendered the anode and iron is rendered the cathode

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Answer: o.125 moles of gas X with a molar mass of 240

Explanation:

2.8 dm3 of gas X at STP has equal mass with 11.2 dm3 of C2H6 at STP. What is the number of mole if gas X has 30 grams?

the molar volume of any gas at STP is the volume of 1 mole at STP

and is 22.4 L

the C2H6 has a volume of 11.2L at STP so it has 0.5 moles

C2H6 has a molar mass of (2 X 12) +(6 X 1) = 24 + 6 = 30

0,5 moles weighs 15 gm at STP with

so 15 gm at STP with 2.8 L for gas X

PV=nRT

P=1 atm

T =273.2k

V =2.8

R =0.082

n = PV/RT = (1 X 2.8)/(0.082 X 273.2) =0.125 moles of gasX

the weight of gas X is 30 gms

so 30/.125 =240 g/mole = molar mass of gas X

An H atom is made up of a nucleus with a +1 charge, as well as a single electron. Therefore, the only positively charged ion possible has charge +1.

I hope this helps!

Answer:

the answer is 150 in centimeters

When tiny droplets of one liquid are finely dispersed within another liquid it is called emulsion.

Emulsion can be defined as the process by which two liquids that are not miscible come together to form a mixture.

The emulsion mixture usually consists of an oil phase and a water phase.

The oil phase appears as droplets when dispersed (mixed with) the water phase.

The uses of emulsion include:

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Tornadoes form when updrafts from thunderstorms begin to interact with strong wind shear and develop a rotating column of air.

Updrafts are powerful vertical currents of air that occur within thunderstorms, caused by the rapid heating of the Earth's surface and the subsequent convective process. These updrafts carry warm, moist air upward, creating a conducive environment for the formation of severe weather phenomena.

When the updrafts encounter wind shear, which is the change in wind speed and direction with height, it can lead to the development of horizontal vorticity. Wind shear creates a rotating motion within the storm, where air at different heights starts to rotate at different speeds, generating a horizontal spin.

As the updraft continues to intensify, it tilts the rotating column of air from horizontal to vertical, forming a mesocyclone. The mesocyclone is a critical component in tornado formation. It acts as a localized area of strong rotation within the storm, extending from the cloud base to the mid-levels of the atmosphere.

Under specific conditions, such as the presence of a strong updraft, a well-developed mesocyclone, and further enhancement from other atmospheric factors, the mesocyclone can contract and intensify into a tornado. The process is complex and influenced by various meteorological factors, but the interaction between updrafts, wind shear, and the development of rotation plays a fundamental role in tornado formation.

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Answer:

Therefore, the partial pressure of oxygen at high altitudes is less than at sea level.

Explanation:

The deep ocean thus has higher oxygen because rates of oxygen consumption are low compared with the supply of cold, oxygen-rich deep waters from polar regions. In the surface layers, oxygen is supplied by exchange with the atmosphere.

Answer:

b

Explanation:

Answer:

B

Explanation:

so A is nosense C and D the question is saying the stament for a being repersentation of solid not whether eletric or not

Answer:

If AT and q are negative, then heat flows from an object into its surroundings. If a substance gains thermal energy, its temperature increases, its final temperature is higher than its initial temperature, then AT>0 and q is positive.