What is formula of matter

Determine the molality of an aqueous solution that is 15.5 percent urea by mass.

DaniilM [7]

15.5% by mass is equivalent 15.5 g urea in 100 g solution or 155 g urea in 1 kg solution. 

we know that molality = moles solute / kg solvent

moles solute = 155 g / 60 g/mol = 2.58 moles urea

Since there are 155 g urea in 1000g solution, hence the solvent is 845 g or 0.845 kg

So:
molality = 2.58 / 0.845 = 3.06 m

3 0

3 years ago

Imagine you are about to investigate what happens when sodium and potassium are mixed together. Before you begin your experiment

inessss [21]

Explanation:

Potassium and Sodium are both metals on the periodic table. Both elements are found on the s-block of the table. Therefore, it is not possible for both of them to combine to form a compound.

For a compound to form two elements must combine in a definite order to given single product.

The combination is facilitated by a loss, gain or sharing of electrons between two species. This leads to an attraction between the combining species.

Both Sodium and potassium would prefer to lose electrons and there is no reason for them to combine to form a compound.

6 0

3 years ago

Law of Universal Gravitation (what factors affect gravity and how?)

olya-2409 [2.1K]

Explanation:

Hey there!

According to the law of gravitation, the factors that affects the gravity are:

Mass of the heavenly bodies.
Distance from the centre of the body to next body.

Mass of heavenly bodies:The mass of heavenly bodies affect the gravity. We know that gravity is directly proportional to the mass of heavenly bodies. so, when the mass is more there is more gravity and where there is less mass there is less gravity.

Distance from the centre of the body to next body: It is one of the factor to influence gravity. When there is more distance there is less gravity and where there is distance more force is there. Is means gravity is inversely proportional to the distance between the bodies.

Hope it helps...

7 0

2 years ago

How you do this?need help with bro HW

steposvetlana [31]

The last question depends on the scientific method.
Scientific Method
1. Make an observation of what u are testing 2. Form a question about ur observations. 3. Make a hypothesis 4. Conduct your experiment 5. Record information and results.
The first question depends what you will need to use first for the experiment.

7 0

3 years ago

What are the formal charges on the sulfur (s), carbon (c), and nitrogen (n) atoms, respectively, in the resonance structure that

sergiy2304 [10]

Answer:

Sulfur: -1

Carbon: 0

Nitrogen: 0

Explanation:

The thiocyanate ion SCN- can have only two resonance structures, which are:

S - C ≡ N <--------> S = C = N

In the first structure, we have one single bond and one triple bond, in this case, the negative charge is located in the sulfur. This is because Sulfur have 6 electrons and those electrons are present in the atom, (see picture below), and counting the electron that is sharing with the Carbon, the total electrons that sulfur has is 7 (It has one more than usual). Carbon and nitrogen are already stable with 0 of formal charge, because carbon can only have 4 electrons which 1 is sharing with sulfur and the other 3 with the nitrogen, and nitrogen have 5 electrons, three sharing with carbon and the other two kept it for itself.

In the second structure, the negative charge of the sulfur is transfered to the nitrogen, meaning that it has 6 electrons the nitrogen (formal charge -1) and carbon and sulfur with 4 and 6 electrons respectively.

Between these two structures, the most stable is the first one basically because Sulfur is a better nucleophile than the Nitrogen, and can form stronger hydrogen bond in acid, giving more stable structure.

7 0

3 years ago

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