5) Calculate the molality of 0.210 mol of KBr dissolved in 0.075kg pure
water?

Answers

Answer 1

Answer:

[tex]\boxed {\boxed {\sf 2.8 \ m }}[/tex]

Explanation:

The formula for molality is:

[tex]m=\frac{moles \ of \ solute}{kg \ of \ solvent}[/tex]

There are 0.210 moles of KBr and 0.075 kilograms of pure water.

[tex]moles= 0.210 \ mol \\kilograms = 0.075 \ kg[/tex]

Substitute the values into the formula.

[tex]m= \frac{ 0.210 \ mol }{0.075 \ kg}[/tex]

Divide.

[tex]m= 2.8 \ mol/kg= 2.8 \ m[/tex]

The molality is 2.8 moles per kilogram


Related Questions


If you begin with 14.0g of TiCl4(1), how many liters of H2O(g) will need?

Answers

Answer:

3.32 L

Explanation:

Step 1: Write the balanced equation

TiCl₄(l) + 2 H₂O(g) → TiO₂(s) + 4 HCl(g)

Step 2: Calculate the moles corresponding to 14.0 g of TiCl₄

The molar mass of TiCl₄ is 189.68 g/mol.

14.0 g × 1 mol/189.68 g = 0.0738 mol

Step 3: Calculate the moles of H₂O needed to react with 0.0738 moles of TiCl₄

The molar ratio of TiCl₄ to H₂O is 1:2. The moles of H₂O needed are 2/1 × 0.0738 mol = 0.148 mol

Step 4: Calculate the volume corresponding to 0.148 moles of H₂O(g)

At standard temperature and pressure, 1 mole of H₂O(g) has a volume of 22.4 L.

0.148 mol × 22.4 L/1 mol = 3.32 L

What is the oxidation number of bromine in the BrO3- ion?

Answers

+5 Hope that helps!!!

____ Al + ____ Cr2O3  ____ Al2O3 + ____ Cr
If the reaction of 23.3 grams of Cr2O3 produces 5.35 grams
of Al2O3, what is the percent yield?

Answers

Answer:

[tex]Y=34.3\%[/tex]

Explanation:

Hello there!

In this case, according to the balanced chemical reaction:

[tex]2Al + Cr_2O_3 \rightarrow Al_2O_3 + 2Cr[/tex]

We notice there is a 1:1 mole ratio between Al2O3 and Cr2O3; thus, the following stoichiometric setup is used to compute the theoretical yield first:

[tex]m_{Al_2O_3 }=23.3gCr_2O_3*\frac{1molCr_2O_3}{151.99gCr_2O_3} *\frac{1molAl_2O_3}{1molCr_2O_3} *\frac{101.96gAl_2O_3}{1molAl_2O_3} \\\\m_{Al_2O_3}=15.6gAl_2O_3[/tex]

Thus, the percent yield turns out:

[tex]Y=\frac{5.35g}{15.6g} *100\%\\\\Y=34.3\%[/tex]

Best regards!

Electrons help create bonds between elements as they lie on the outside of an
atom.

Answers

uh , what’s the question ?

How many atoms are in 4.5 moles of nitrogen

Answers

Answer:one mole of stuff (atoms, molecules, eggses), there are NA individual items of that stuff. So, there are 4.5 × NA BCl3 molecules; i.e. 4.5 × 6.022×1023 ≅ 27×1023 individual molecules of BCl3

Explanation:

Answer:

[tex]\boxed {\boxed {\sf About \ 2.7 *10^{24}\ atoms\ N }}[/tex]

Explanation:

To convert from moles to atoms, Avogadro's Number: 6.022*10²³ must be used. This number tells us the amount of particles (atoms, molecules, etc) in 1 mole of a substance. In this case, the particles are atoms of nitrogen.

[tex]\frac {6.022 *10^{23} \ atoms \ N}{1 \ mol \ N}[/tex]

Multiply by the given number of moles: 4.5

[tex]4.5 \ mol \ N *\frac {6.022 *10^{23} \ atoms \ N}{1 \ mol \ N}[/tex]

The moles of nitrogen will cancel.

[tex]4.5 \ *\frac {6.022 *10^{23} \ atoms \ N}{1 }[/tex]

The denominator of 1 can be ignored.

[tex]4.5 \ *{6.022 *10^{23} \ atoms \ N}[/tex]

[tex]2.7099*10^{24} \ atoms \ N[/tex]

The original measurement of moles had 2 significant figures, so our answer must have the same. For the number we calculated, that is the tenth place. The 0 in the hundredth place tells us to leave the 7.

[tex]2.7 *10^{24}\ atoms\ N[/tex]

There are about 2.7*10²⁴ atoms of nitrogen in 4.5 moles.

5. If the reaction of carbon monoxide and oxygen gas in question 2
produced 7.03E24 molecules of CO2, what is the mass in grams? Use
44g/mol for M.M. of CO2 and round your answer to the nearest whole
number. *

Answers

Answer: The mass in grams is 514.8.

Explanation:

According to avogadro's law, 1 mole of every substance weighs equal to molecular mass and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.

To calculate the number of moles, we use the equation:

[tex]\text{Number of moles}=\frac{\text{Given molecules}}{\text{Avogadros number}}[/tex]

given molecules = [tex]7.03\times 10^{24}[/tex]  

Putting in the values we get:

[tex]\text{Number of moles}=\frac{7.03\times 10^{24}}{6.023\times 10^{23}}=11.7moles[/tex]

mass of [tex]CO_2=moles\times {\text {Molar mass}}=11.7mol\times 44g/mol=514.8g[/tex]

The mass in grams is 514.8.

which has more gravity
A. Earth
B. Sun
C. Saturn

Answers

B

the sun!

yay

!!!!!!!!!!!

Answer:

EARTH

Explanation:

Earth‘s gravity, as already noted, is equivalent to 9.80665 m/s² (or 32.174 ft/s²). This means that an object, if held above the ground and let go, will accelerate towards the surface at a speed of about 9.8 meters for every second of free fall.

Which of Newton's Three Laws is BEST described by the following statement: A ball dropped from the 10th story of a hotel had more force than when the same ball was dropped from the 5th story of the same hotel

Answers

Answer:

I believe the answer is Newton's Second Law

Explanation:

Newton's Second Law states that the acceleration of an object will count on how much mass and the amount of force that is applied.

The bowling ball was dropped from the 10th story window and had more force than when the ball was dropped from the 5th story window because the 10th story window gave the bowling ball more acceleration.

Use the drop-down menus to label the graph
according to its type.

Answers

Where is the picture of the graph

Answer:

relation (but not a function)

Explanation:

c on edge

Why are watersheds important for the maintenance of water quality? Choose all that apply.

Select 2 correct answer(s)
Question 3 options:

they can transfer pollutants


their soil and plants can filter and clean water


they cause precipitation and acid rain


they cause floods

Answers

Answer:

its A and D

Explanation:

i took the quiz

Answer:

a and d

Explanation:

unscramble the answer
The components of a simple circuit are the following:

1. SURCOURFOECRTEN
2. ICEEVD
3. RISEW
4. CSITHW

Answers

Answer:

1counterforces

2device

3wires

4switch

Unscramble the words:
1: COUNTERFORCE
2: DEVICE
3: WIRES
4: SWITCH

Given the following balanced chemical equation:
N2(g) + 3H2(g) + 2NH3(8)
What is the maximum amount of NH3(g) that can be produced from 2.0 mol H2(g)? Assume that N2(g) is the excess reactant.

Answers

Answer:

22 g

Explanation:

Step 1: Write the balanced equation

N₂(g) + 3 H₂(g) ⇒ 2 NH₃(g)

Step 2: Calculate the moles of NH₃ produced from 2.0 moles of H₂

The molar ratio of H₂ to NH₃ is 3:2.

2.0 mol H₂ × 2 mol NH₃/3 mol H₂ = 1.3 mol NH₃

Step 3: Calculate the mass corresponding to 1.3 moles of NH₃

The molar mass of NH₃ is 17.03 g/mol.

1.3 mol × 17.03 g/mol = 22 g

Draw the structure of the major organic product(s) for the following reaction between an acetylenic anion and an alkyl halide. (The reaction stoichiometry is 1:1.) A carbon carbon triple bond where carbon 1 is a carbanion with a lone pair and carbon 2 is bonded to methyl. This reacts with a 5 carbon chain where carbon 3 has a bromine substituent.

Answers

Answer:

See explanation below

Explanation:

In this case, we are having a reaction between an anion and alkyl halide. The carbon 1 of the anion will act as nucleophile and will attack the electrophile, which is 5 carbon chain with the bromine in the third carbon.

Now, the nucleophyle is an alkyne of 3 carbon. According to the description, it should be:

CH₃ - C ≡ C⁻

And the alkyl halide is:

CH₃ - CH₂ CH(Br) - CH₂ - CH₃

And the final product after the reaction would be the following:

CH₃ - C ≡ C - CH - (CH₂CH₃)₂

However, in the attached picture you can see this better and the mechanism of reaction.

Hope this helps

What happens to a linguist when it releases enough energy

Answers

Answer:

When a liquid releases enough energy, the liquid will freeze and turn into a solid. Phase changes are what causes one state of matter to turn into another. All phase changes are physical changes.

Explanation:

if ur really saying liquid a person accomplished in languages

especially : one who speaks several languages ?

please mark as brainliest

If you are doing stoichiometry and it asks you to go from grams of one substance to grams of a new substance, how many steps (how many boxes) would you draw in your setup?

a.1

b.2

c.3

d.4

You do not have to explain if you want to.

Answers

Answer:

a.b

c

d

a

d

i think it is it or east be responsible

make me the brainyst please

How many grams are in 2.49 x 10^24 atoms of Hg?

Answers

Answer:

[tex]m_{Hg}=829.4gHg[/tex]

Explanation:

Hello there!

In this case, considering the Avogadro's number, which helps us to realize that 1 mole of mercury atoms contains 6.022x10²³ atoms and at the same time 1 mole of mercury weights 200.59 g, we obtain:

[tex]m_{Hg}=2.49x10^{24}atoms*\frac{1mol}{6.022x10^{23}atoms} *\frac{200.59g}{1molHg}\\\\m_{Hg}=829.4gHg[/tex]

Best regards!

Two experiments were conducted: 4.125 g of copper(II) oxide, CuO2, was reduced by heating at high pressure with excess hydrogen to yield 3.294 g of copper Cu. 1.179 g of copper Cu was dissolved in nitric acid to yield copper(II) nitrate, which was converted to 1.476 g copper(II) oxide, CuO2, on ignition. Show that the results illustrate the law of definite proportions by calculating the percentage of oxygen in copper(II) oxide in experiments 1 and 2.

Answers

Answer:

Explanation:

4.125 g of copper oxide contains 3.294 g of Cu . Rest is oxygen

oxygen is 4.125 - 3.294 = .831 g

Ratio of oxygen and copper = .831 : 3.294

.831 / .831 : 3.294 / .831

= 1 : 3.96

1 : 4 ( Approx )

percentage of oxygen in copper oxide = 20 % approx

in the second experiment ,

1.476 g of copper oxide is formed from 1.179 g of Cu

oxygen in this copper oxide = 1.476 - 1.179 = .297 g

Ratio of oxygen and copper

.297 : 1.179

.297/.297 : 1.179/ .297

1 : 3.96

1 : 4 ( approx )

percentage of oxygen in copper oxide = 20 % approx

So it follows the law of definite proportions .

The most prominent feature of ocean topography discovered in the 1960s was:

a mountain ridge which circles the earth
subduction zones
volcanic activity at the ocean bottom
seamounts

Answers

answer:

a mountain ridge which circles the earth

subduction zones


Hydrogen gas is a product of the reaction of
magnesium with hydrochloric acid. How many
liters of hydrogen gas are produced from the
complete reaction of 146.5 g magnesium metal at
2.40 atm and a temperature of 314 K?
(Mg = 24.30 g/mol)
Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)
Hint: R = 0.0821 L atm/(mol K)

Answers

Answer:

64.7

Explanation:

Answer:

64.7 is the answer

hope this helps

have a good day :)

Explanation:

Help me please omg

Answer the following question:

How many moles of ammonia are in 375. mL of a 2.25 M aqueous ammonia solution?

Find the numerical answer for this question and make sure to include the following:

What is the chemical formula for ammonia?
What is the formula for molarity?
When you give your numerical answer, what is the correct significant figures and how do you know that is the correct amount?

Answers

Answer:

NH₃

M = n/V(L)

0.844 mol (Both numbers have 3 significant figures so the result has 3 significant figures as well)

Explanation:

Step 1: Given and required data

Volume of solution (V): 375. mLMolar concentration of the solution (M): 2.25 MChemical formula for ammonia: NH₃

Step 2: Calculate the moles (n) of ammonia (solute)

Molarity is equal to the moles of solute divided by the liters of solution.

M = n/V(L)

n = M × V(L)

n = 2.25 mol/L × 0.375 L = 0.844 mol (Both numbers have 3 significant figures so the result has 3 significant figures as well)

2 Cu + Cl2 ----> 2 Cuci
If 1.64 moles of chlorine is reacted with 3.23 moles of copper, how many grams of copper I chloride will be made?
(The next question will ask about the limiting and excess reactants for this reaction)
o 320 g
O 160 g
O 162 g
O 325 g

Answers

Answer:

320 g.

Explanation:

Hello!

In this case, according to the balanced chemical reaction, we can compute the grams of copper I chloride produced by each reactant, as shown below:

[tex]m_{CuCl}^{by\ Cu}=3.23molCu*\frac{2molCuCl}{2molCu}*\frac{99.0gCuCl}{1molCuCl} =320gCuCl\\\\m_{CuCl}^{by\ Cl_2}=1.64molCl_2*\frac{2molCuCl}{1molCl_2}*\frac{99.0gCuCl}{1molCuCl} =325gCuCl[/tex]

Thus, since copper produces the fewest grams of CuCl, we infer it is the limiting reactant, therefore the correct mass of copper I chloride is 320 g.

Best regards!

A reaction was set up to convert an alcohol to a carbonyl. Samples of the reaction mixture were checked by infrared spectrometry every couple of minutes. Use the infrared spectra provided to determine if the reaction mixture contains: pure alcohol, a mixture of alcohol and carbonyl, or pure carbonyl. The reaction mixture contains pure carbonyl. pure alcohol. mixture of alcohol and carbonyl. The reaction mixture contains mixture of alcohol and carbonyl. pure carbonyl. pure alcohol.

Answers

Answer:

First spectrum = contains only alcohol Compound.

Second spectrum= Contains both alcohol and carbonyl compounds.

Explanation:

The concept known as "spectroscopy'' is an important aspect of Chemistry. It is used in the identification of chemical compounds. Some of the techniques used in spectroscopy is through the use of NMR, IR spectroscopy and UV-Vis spectroscopy.

This question is about IR spectroscopy. Here each functional group has its own unique frequency of absorption. For instance the frequency of absorption of Alkane, C- H( stretch) is 2850 - 3000, alkyne, C-H( stretch) is 3300, amine, N-H(bending) is 1600 and so on.

For the characteristic frequency of absorption found in OH(stretch) is 3300 - 3700. This can be seen in the spectrum given. Thus, OH bond is present.

For carbonyl group, C= O the characteristic absorption frequency is 1670-1820. This frequency can not be found in the first spectrum. But checking the second spectrum a frequency of 1700 can be seen.

Thus, the C=O bond is absent on the first spectrum but present in the second spectrum.

In the second spectrum too, the characteristic frequency of absorption of 3300 is found. Thus, in the second spectrum the compound have both OH and C=O.

niling Reactants
POSSIBLE POINTS: 4.55
6 K + Cr2S3 ----> 2 Cr + 3 KZS
A scientist combines 151 grams of potassium and 151 grams of chromium III sulfide, how many moles of chromium will be
made?
(The next question will ask about the limiting and excess reactants for this reaction)
O 11.6 g
O 0.377 g
O 1.29 g
O 1.51 g

Answers

11.6 is the correct answer I believe

write the balanced chemical equation for lab preparation of oxygen gas by using heat​

Answers

Answer:

O + O ---Δ----> O2

Explanation:

plz follow me friend

Answer:

hello my ne is yash follow me please

Convert the volume, nm^3, to liters (L) by using the box dimensions of 4nm x 8.75nm x 10nm. Use the conversion factor of 1 L = 1 dm^3. Do not convert directly from nm^3 to dm^3

Answers

Answer:

[tex]V=3.50x10^{-22}L[/tex]

Explanation:

Hello there!

In this case, given the dimensions of the box, we first compute the volume by multiplying each side:

[tex]V=4nm*8.75nm*10nm=350nm^3[/tex]

Next, we apply the following conversion factor in order to obtain the corresponding liters:

[tex]V=350nm^3*(\frac{1m}{10^9nm} )^3*\frac{1000L}{1m^3} \\\\V=350nm^3*\frac{1m^3}{10^{27}nm^3} *\frac{1000L}{1m^3}\\\\V=3.50x10^{-22}L[/tex]

Best regards!

short note on dung fertilization ​

Answers

Answer:

Most manure consists of animal feces; other sources include compost and green manure. Manures contribute to the fertility of soil by adding organic matter and nutrients, such as nitrogen, that are utilised by bacteria, fungi and other organisms in the soil.

Explanation:

Hope it is helpful....

Answer:

Animal manure, such as chicken manure and cow dung, has been used for centuries as a fertilizer for farming. It can improve the soil structure (aggregation) so that the soil holds more nutrients and water, and therefore becomes more fertile. ... Manure is also commercially composted and bagged and sold as a soil amendment.

Explanation:

Ge(NO2)2 whats the name of this formula?

Answers

Answer:

Germanium monoxide

hope this helps :)

Three mixtures were prepared from three very narrow molar mass distribution polystyrene samples with molar masses of 10,000, 30,000 and 100,000 g mol−1 as indicated below: (a) Equal numbers of molecules of each sample (b) Equal masses of each sample (c) By mixing in the mass ratio 0.145:0.855 the two samples with molar masses of 10,000 and 100,000 g mol−1 For each of the mixtures, calculate the number-average and weight-average molar masses and comment upon the meaning of the values.

Answers

Answer:

(a). 46,666.7 g/mol; 78,571.4 g/mol

(b). 86950g/mol; 46,666.7 g/mol.

(c). 86950g/mol; 43,333.33 g/mol

Explanation:

So, we are given the molar masses for the three samples as: 10,000, 30,000 and 100,000 g mol−1.

Thus, the equal number of molecule in each sample = ( 10,000 + 30,000 + 100,000 ) / 3 = 46,666.7 g/mol.

The average molar mass = [ ( 10,000)^2 + (30,000)^2 + 100,000)^2] ÷ 10,000 + 30,000 + 100,000 = 78,571. 4 g/mol.

(b). The equal masses of each sample = 3/[ ( 1/ 10,000) + (1/30,000 ) + (1/100,000) ] = 20930.23 g/mol.

Average molar mass = ( 10,000 + 30,000 + 100,000 ) / 3 = 46,666.7 g/mol.

(c). Equal masses of the two samples = (0.145 × 10,000) + (0.855 × 100,000)/ 0.145 + 0.855 = 86950g/mol.

The weight average molar mass = 1.7 + 10,000 + 100,000/ 1.7 + 1 = 43,333.33 g/mol.

(trying this again because this test is due at 3 and paimon has to get this done or she will fail!! paimon will try to give brainlist if brainly lets her!!)

The _________________molecules in the food we eat are_____________.
A. Enzyme, water
B. Small, insoluble
C. Large, insoluble
D. Enzyme, insoluble

Answers

it should be b. or c. my guess is b. because molecules are small. so i think it’s b. (im not entirely sure though)

The hydronium ion concentration of an aqueous solution of 0.502 M pyridine (a weak base with the formula C5H5N) is

Answers

Answer:

1.99×10¯¹⁴ M

Explanation:

We'll begin by writing the balanced dissociation equation of pyridine. This is illustrated below:

C₅H₅N + H₂O <=> C₅H₆N⁺ + OH¯

From the balanced equation above,

1 mole of C₅H₅N produced 1 mole of OH¯.

Therefore, 0.502 M C₅H₅N will also produce 0.502 M OH¯.

Finally, we shall determine the concentration of hydronium ion, H₃O⁺ in the solution. This can be obtained as follow:

Concentration of Hydroxide ion [OH¯] = 0.502 M

Concentration of hydronium ion [H₃O⁺] =?

[H₃O⁺] [OH¯] = 1×10¯¹⁴

[H₃O⁺] × 0.502 = 1×10¯¹⁴

Divide both side by 0.502

[H₃O⁺] = 1×10¯¹⁴ / 0.502

[H₃O⁺] = 1.99×10¯¹⁴ M

Thus, the concentration of hydronium ion, H₃O⁺ in the solution 1.99×10¯¹⁴ M

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