All categories

2 years ago

Glucose has a molecular mass of 180 daltons. to make a 2-molar (2 m) solution of glucose, __________.

1 answer:

6 0

The molality of a substance is the moles of the substance present in 1000mL or 1L or 1Kg of water. 1L of water is equivalent to 1Kg of water as the density of water is 1g/mL. The molecular mass of a substance is represent the amount of the substance present in 1 mole of the compound. Here the molar mass of glucose is 180 daltons thus 1 mole of glucose is equivalent to 180 daltons. To prepare 1 molar glucose solution 180 daltons of glucose have to dissolve in 1L of water. So to prepare 2 molar glucose solution (180×2) = 360 daltons of glucose have to dissolve in 1000mL or 1L or 1Kg of water.

You might be interested in

At 50 degree C pK_w = 13.26. What is the pH of pure water at this temperature?

Ksivusya [100]

Answer:

6.63

Explanation:

From the relationship;

pH = pKw/2

Pkw = 13.26

Then it follows that;

pH = 6.63

Hence if. pKw = 13.26, the pH = 6.63

8 0

2 years ago

A precipitate forms when mixing solutions of sodium fluoride (NaF) and lead II nitrate (Pb(NO3)2). Complete and balance the net

Margarita [4]

Answer:

Pb^2+(aq) + 2F-(aq) → PbF2(s)

Explanation:

Step 1: Data given

sodium fluoride = NaF

lead(II)nitrate Pb(NO3)2

Step 2: The unbalanced equation

NaF(aq) + Pb(NO3)2(aq) → PbF2(s) + NaNO3(aq)

Step 3: Balancing the equation

NaF(aq) + Pb(NO3)2(aq) → PbF2(s) + NaNO3(aq)

On the left side we have 2x NO3 (in Pb(NO3)2), on the right side we have 1x NO3 (in NaNO3). To balance the amount of NO3 we hvae to multiply NaNO3 on the right side by 2.

NaF(aq) + Pb(NO3)2(aq) → PbF2(s) + 2NaNO3(aq)

On the left side we have 1x Na (in NaF), on the right side we have 2x Na (in 2NaNO3). To balance the amount of Na we have to multiply NaF on the left side by 2. Now the equation is balanced.

2NaF(aq) + Pb(NO3)2(aq) → PbF2(s) + 2NaNO3(aq)

Step 4: Calculate net ionic equation

The net ionic equation, for which spectator ions are omitted - remember that spectator ions are those ions located on both sides of the equation - will , after canceling those spectator ions in both side, look like this:

2Na+(aq) + 2F-(aq) + Pb^2+(aq) + 2NO3-(aq) → PbF2(s) + 2Na+(aq) + NO3-(aq)

Pb^2+(aq) + 2F-(aq) → PbF2(s)

4 0

2 years ago

What would have happened to your results if during the dehydration some of the copper (ii) sulfate splatter out of the crucible-

lidiya [134]

Answer : The results would show more amount of water in the hydrated sample.

Explanation :

The amount of water of crystallization can be found by taking the masses of hydrated copper sulfate and anhydrous copper sulfate.

The difference in masses indicates the mass of water lost during dehydration process.

If during dehydration process, some of the copper sulfate spatters out of the crucible, then this would give us less mass for anhydrous sample than the actual.

As a result, the difference in masses of hydrated sample and the anhydrous sample would be more.

Therefore the results would show more amount of water in the hydrated sample.

4 0

2 years ago

The nuclear equation is incomplete. Superscript 239 Subscript 94 Baseline P u + Superscript 1 Subscript 0 Baseline n yields Supe

Likurg_2 [28]

Answer:

The correct option is the first option

Explanation:

The equation described in the question is shown below

²³⁹₉₄Pu +¹₀n ⇒ ¹⁰⁰₄₀Zr + blank + 2¹₀n

This equation is a nuclear fission because it involves the splitting of a heavy nucleus, Plutonium (Pu), into smaller nuclei, Zirconium (Zr) and an unknown nuclei.

The law of conservation of matter states that matter can neither be created nor destroyed hence in other to get the missing atom, we must know the total number of subscripts (mass number) and superscripts (atomic number) on both sides.

The total mass number on the reactant side is 239 + 1 = 240

The total atomic number on the reactant side is 94 + 0 = 94

While, The total mass number on the product side is 100 + 2(1) = 102

The total atomic number on the product side is 40 + 2(0) = 40

To determine the missing atom, you subtract the the total atomic number of the product from that on the reactant side; 94 - 40 = 54

The atom with the atomic number 54 is Xenon,

To determine the mass number of the xenon isotope involved, you subtract the the total mass number of the product from that on the reactant side; 240 - 102 = 138.

Hence, the particle that completes the equation is ¹³⁸₅₄Xe, the first option

5 0

2 years ago

A mixture of carbon dioxide and an unknown gas was allowed to effuse from a container. The carbon dioxide took 1.25 times as lon

Aleks04 [339]

Answer:

Explanation:

From Graham's law, time taken to diffuse is directly proportional to the molecular mass of the gases. For two different gases.

t1/t2=√m1/m2

Since gas 1 diffuse 1.25 times as slowly as gas 2 and gas 1 is CO2 with m as 44g

1.25/1=√44/m2

Therefore m2=28g CO

7 0

2 years ago