All categories

3 years ago

Answer seventeen please

Chemistry

1 answer:

kondor19780726 [428]3 years ago

3 0

A. Ammonium = polyatomic ion
B. Oxygen = compound
C. Silver = element
D. Nitrate = polyatomic ion
E. Helium = element
F. Water = polyatomic ion
G. Nitrogen = element
H. Carbon dioxide = compound

You might be interested in

Convert 26.02 x 1023 molecules of C2H8 to grams. Round your answer to the hundredths place.

Akimi4 [234]

No of molecules=26.02×10²³molecules

No of moles

26.02×10²³/6.023×10²³
4.3mol

Molar mass

C2H8
2(12)+8(1)
24+8
32g/mol

Mass

Moles×Molar mass
32(4.3)
137.6g

6 0

2 years ago

Why is the periodic table such as useful tool for chemist?

Tomtit [17]

The periodic table is useful tool for chemist since we can see what is the atomic and mass number for each atom.

Atomic number is equal to how many protons and electrons in it

Mass number is equal to protons + Neutrons.

3 0

3 years ago

An oxidation-reduction reaction that is also a synthesis reaction

Aleonysh [2.5K]

The example of a chemical combination that can also be said to be a synthesis reaction is; $2Mg(s) +O_{2} (g) -- > 2 MgO(s)$

<h3>What is a synthesis reaction?</h3>

We know that the meaning of the synthesis reaction is quite central as we attempt to answer the question that is lying right before us here. If we are talking about the synthesis reaction then our mind must have to go to the kind of reaction in which there is the combination of two or more so as to produce a single compound.

As we are talking about the synthesis reaction, we would have to look at the reaction that would give rise to a single product as it has been written. Let us also recall that we have been told that the reaction is a oxidation-reduction reaction thus there is a change in oxidation number in the process of the reaction as shown.

Learn more about synthesis reaction:brainly.com/question/16987748

#SPJ1

7 0

1 year ago

2H2 + O2 → 2H2O

pantera1 [17]

Okay
Mr (H2O)= 18g
therefore moles of H2O
is 720.8/18= 40.04mol
the ratio of H2 to O2 to H2O is
2 : 1 : 2
so moles of H2 is same as H2O here
H2= 40.04moles

moles of O2 is half
so 40.04 x 0.5
20.02moles

grams of O2 is
its moles into Mr of O2
that's 20.02 x 32 = 640.64g

6 0

3 years ago

At 55.0 ∘C, what is the vapor pressure of a solution prepared by dissolving 78.4 g of LiF in 253 g of water? The vapor pressure

ddd [48]

Answer:

82.5 mmHg

Explanation:

The vapor pressure of a solution that contains a non-volatile solute will depend on the mole fraction of the solvent and on the vapor pressure of the pure solvent at the same temperature.

P sol= χsolvent ⋅ P∘solvent, where

Psol - the vapor pressure of the solution

χ solvent - the mole fraction of the solvent

P ∘solvent - the vapor pressure of the pure solvent

Now, the most important thing to realize here is that lithium fluoride,

LiF , a soluble ionic compound, will dissociate completely in aqueous solution to form lithium cations and fluoride anions.

LiF (aq] → Li+(aq] + F − (aq]

Notice that every mole of lithium fluoride produces one mole of lithium cations and one mole of fluoride anions.

This means that you get a total of two moles of ions for every one mole of lithium fluoride in the solution.

Use lithium fluoride's molar mass to determine how many moles would be found in the given sample

78.4g⋅ (1 mole LiF /25.94 g) = 3.022 moles LiF

This means that the solution will contain

3.022 moles LiF ⋅ (2 moles ions /1 mole LiF) = 6.044 moles ions

Now, water's mole fraction in this solution will be equal to the number of moles of water divided by the total number of moles present in the solution.

To get the number of moles of water, use its molar mass

253 g ⋅ (1 mole H 2O / 18.015 g) = 14.044 moles H 2O

This means that water's mole fraction will be

χwater = 14.044 moles / (14.044 +6.044 )moles = 0.6991

The vapor pressure of the solution will thus be

Psol= 0.6991 ⋅ 118 mmHg = 82.5 mmHg

7 0

3 years ago