describe how oxides of nitrogen are produced when petrol is burned in car engines !!HELP!!

Answer:

Explanation:

Solution required is .15 M 500 mL sodium fluoride .

molecular weight of sodium fluoride = 42

one mole of sodium fluoride = 42 grams

No of moles contained in the solution of .15M , 500 mL solution

= .15 x 0.5 moles = .075 moles

1 mole = 42 g

.075 moles = .075 x 42 = 3.15 grams .

So mass of sodium fluoride required = 3.15 g .

Answer: Mutations can cause instant adaptations, while natural selection is the process by which adaptations occurs over a series of generations. Adaptations are changes or processes of changes by which an organism or species becomes better suited for its environment. A mutation is an alteration of the DNA sequence.

Answer:

A. avoid talking to Anna altogether and stay out of her way

B. ask her manager for advice

C. check with Gary to see if there is any gossip about what's going on with Anna

D. take a curt approach of her own to show Anna how it feels

Explanation:

ANSWER: B.

Answer: here is your answer

Explanation:

The oxygen family consists of the elements that make up group 16 on the periodic table: oxygen, sulfur, selenium, tellurium, and polonium. These elements all have six electrons in their outermost energy level, accounting for some common chemical properties among them.

Answer:

they all have 6 valence electrons

Explanation:

all elements in group 16 have 6 valence electrons

Answer:

H2SO4

Explanation:

Firstly,

2.056% hydrogen = 2.056g of H

32.69% Sulphur = 32.69g of S

65.26% oxygen = 65.26g of O

Next, we convert each mass into moles by dividing by their respective molar mass:

H = 1, S = 32, O = 16

H = 2.056/1 = 2.056mol

S = 32.69/32 = 1.021mol

O = 65.26/16 = 4.078mol

Next, we divide each mole value by the smallest mole value (1.021)

H = 2.056/1.021 = 2.01

S = 1.021/1.021 = 1

O = 4.078/1.021 = 3.99

Approximately the ratio of H to S to O is 2:1:4, hence, the empirical formula for H, S and O is H2SO4.

The empirical formula of a chemical compound is the simplest whole-number ratio of atoms present in a compound

The correct answer of the following is [tex]H_2SO_4[/tex]

The data is given as follows:-

We have to find the moles in the reaction.

The mas of the element is as follows:-

After solving the equation we get

[tex]H = \frac{2.056}{1} = 2.056mol\\\\S = \frac{32.69}{32} = 1.021mol\\\\O = \frac{65.26}{16} = 4.078mol[/tex]

Next, we divide each mole value by the smallest mole value (1.021)

[tex]H = \frac{2.056}{1.021} = 2.01\\\\S = \frac{1.021}{1.021} = 1\\\\O = \frac{4.078}{1.021} = 3.99[/tex]

The ratio of H to S to O is 2:1:4,

Hence, the empirical formula for H, S, and O is [tex]H_2SO_4.[/tex]

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The mass of an object is the product of its volume and density. The mass of a the object with a volume of 825 cm³ and a density of 13.6 g/cm³ is 11220 g.

Density of substance is the measure of its mass per unit volume. It describes how closely its particles are packed. Density depends on the bond type, temperature and pressure.

Volume of the object is the space occupied by its particles. Volume can be expressed in L, ml, cm³, dm³ etc. Only solids and liquids has a definite volume and the volume of gases is that of the container.

Give that, volume of the object = 825  cm³

density =  13.6 g/cm³

Mass = volume × density

m = 825  cm³ ×  13.6 g/cm³ = 11220 g

Therefore, the mass of the object is 11220 g.

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Answer:

Grass

Explanation:

On a hot summers day, while barefoot Concrete normaly has heat absorbed into it. (Or on top) So when you go to Walk on it, It normally burns the heel.

Hope I helped and Have a great day!

brainliest?

Answer:

grass

Explanation:

the concrete has a higher specific heat capacity and is basically hotter than the grass which has a lower one

Answer: [tex]C_3H_8+5O_2\rightarrow 3CO_2+4H_2O[/tex]

Explanation:

According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.

The balanced chemical equation for combustion of propane will be :

[tex]C_3H_8+5O_2\rightarrow 3CO_2+4H_2O[/tex]

Answer:

European stability mechanism

Answer:

Pseudoscience

Explanation:

Predicting the future based solely on the position of the planets is an example of pseudoscience.

Pseudoscience is a body of knowledge that is not based on the scientific method but on some unverifiable/unprovable claims.

Predictions about the future can only be valid if it is based on the scientific method, not just about the position of the planet. The scientific method involves observation, hypothesis formulation, testing of the hypothesis through repeatable experiments, and arriving at conclusion.

Any other statement or belief that is not based on these procedures is said to be pseudoscientific.

Answer:

The answer to your question is pseudoscience.

Explanation:

I took the module 1 exam and got it right, yesterday.

Answer:

Heredity is when you have gotten either physical or mental traits from your parents.

Inherited in Biology: Getting traits from your parents

Inherited outside Biology: is the practice of passing on private property, titles, debts, privileges, rights, and obligations upon the death of an individual.

Explanation:

Answer:

D Nimbostratus

Explanation:

Answer:

Three main parts are Protons (pos charge) Neutrons (no charge) Electrons (negative charge) and the electron is found on the outside of the nucleus

Explanation:

The mole fraction of sulfuric acid : 0.073

Given

3.75 M sulfuric acid solution that has density of 1.230 g/mL

Required

The mole fraction

Solution

3.75 M = 3.75 mol/L

For 1 L solution :

mass of solution = 1230 g

mass Sulfuric acid : 3.75 mol x 98 g/mol=367.5 g

mass water = 1230-367.5 = 862.5 g

mol water = 862.5 : 18 g/mol= 47.92

mol total = 3.75 + 47.92 = 51.67

mole fraction of sulfuric acid :

= 3.75 : 51.67

= 0.073

Answer:

19.5g

Explanation:

Given parameters:

Volume of propane gas = 9.95L

Unknown:

Mass of propane gas =  ?

Solution:

To solve this problem, find the number of moles first.

    At STP;

        22.4L of gas makes up 1 mole

         9.95L of gas will have a [tex]\frac{9.95}{22.4}[/tex]    = 0.44mole

So;

   Mass of propane gas  = number of moles x molar mass

Molar mass of propane  = 3(12) + 8(1)  = 44g/mol

    Mass  = 0.44 x 44  = 19.5g

Answer:

2CH4 ------> 3H2 + C2H2

Explanation:

The law of conservation of mass states that atoms can neither be created nor destroyed in a chemical reaction.

The implication of this law is that the number of atoms of each element on the reactant side must be equal to the number of atoms of each element on the product side.

This law is only obeyed by the reaction, 2CH4 ------> 3H2 + C2H2

There were eight atoms of H on the left hand side as well as the right and side of the reaction equation. There were two atoms of C on both the left and right hand sides of the reaction equation respectively. Hence, the law was obeyed here.

Answer:

12 grams

Explanation:

Electrons do not contribute to mass. The proper unit to use is G

Answer:

HOLY WOAH

Explanation:

YES

Answer:

it's easier to look it up

Explanation:

Answer:

It’s false

Explanation:

it could be true if the question mentioned alkaline solution

Answer:

True

Explanation:

Phenolphthalein is colorless in the presence of an acid and turns pink in the presence of a base.

Answer: Reactant

Explanation:

In simple wording, Water act as a reactant and it broke or we can say split the larger molecule in the smaller ones, The H and OH bonds are attached to the two products that are formed after the reaction. Another process in which water is used as an important reactant is photosynthesis.

Answer:

Explanation:

4

Answer:

C6H10Cl2

Explanation:

Convert mass % to mass

100g of the compound contains from each elements: 46,3g Cl; 47,05g C and 6,63g H

Molar mass

Cl = 35.5 g/mol

C = 12 g/mol

H = 1 g/mol

Find the number of moles:

Chlorine: 46.4g /35.5g/mol = 1,3 moles

Carbon: 47,05g/12 g/mol = 3,92 moles

hydrogen: 6,63g/1g/mol = 6,63 moles

Molar fraction:

Cl = 1,30/ 1,30 = 1

C = 3,92/ 1,30 = 3,01

H = 6,63/ 1.30 = 5,01

C3H5Cl = 76,5 g/ mol x 2  = 153 g/ mol

So multiply the molecular formula by two = C6H10Cl2

The final volume : 807.69 cm³

Given

Initial volume : 840 cm³

Initial pressure : 750 mmHg

Final pressure : 780 mmHg

Required

The final volume

Solution

Boyle's Law  

At a fixed temperature, the gas volume is inversely proportional to the pressure applied  

[tex]\tt p_1V_1=p_2.V_2\\\\\dfrac{p_1}{p_2}=\dfrac{V_2}{V_1}[/tex]

Input the value :

V₂=(P₁V₁)/P₂

V₂=(750 x 840)/780

V₂=807.69 cm³

We use roman numerals to indicate the oxidation state of metal atoms when naming compounds especially in the case of coordination compounds. It is a standard system of nomenclature.

Oxidation state of a species is the number electrons gained or lost. Oxidation state increases if electrons are lost from the atom and it will be decreased if electrons are gained.

For example, copper is in + 2 oxidation state in CuSO₄, thus it can be indicated as Cu(II). Copper can exists is +3 oxidation too. Thus the representation will be Cu (III).

All the transition metals like copper exhibit various oxidation state. So it is important to indicate in which oxidation state they are in a particular compound. In the compound Fe₂O₃, iron is in + oxidation state whereas in FeSO₄, it can be +2 . Thus it is important to note whether it is Fe (II) or Fe (III).

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Answer:

combination, decomposition, single-replacement, double-replacement, and combustion.

Explanation: