tính chất hoá học của Cu

Answer:

The reaction between zinc and HCl is given by the symbolic equation

Zn + HCl → ZnCl2 + H2.

Answer:

d. 46.5 g

Explanation:

First, you need to start with a properly balanced equation:

N₂H₄(l) + 3O₂(g) -> 2NO₂(g) + 2H₂O(l)

Then, find the moles of water produced:

2H = 2.01568 amu

O = 15.999 amu

________________

18.01468 amu

52.4 g ÷ 18.01468 amu = 2.9087 moles

The mole ratio in our balanced formula between N₂H₄ : H₂O is 1 : 2, so divide moles of H₂O by 2 to get moles of N₂H₄

2.9087 moles ÷ 2 = 1.45435 moles of N₂H₄

Then, calculate the atomic mass of N₂H₄:

2N = 28.0134 amu

4H = 4.03136 amu

________________

32.04476 amu

Finally, calculate the mass in grams of N₂H₄:

1.45435 moles • 32.04476 amu = 46.604 g

Answer: Fluorite

Explanation: Minerals are naturally occurring inorganic materials with definite chemical compositions and definite physical properties. Hardness and Streak are both physical characteristics used in identifying minerals. The colour of a mineral’s powder defines its streak (it does not change from mineral to mineral) and a streak of white shows that such mineral has a calcium fluoride making it a fluorite.  To check streak, one simply scrapes the mineral across an unglazed porcelain plate.

Hardness on the one hand, is the resistance to cutting, scratching, abrasion or indentation of minerals.  Mineral hardness is specified by the Mohs hardness scale when working with hand samples, and the scale ranges from 1 (very soft like talc) to 10 (as hard as diamond). A hardness of 4 also put such mineral into the fluorite range indicating that it is harder than calcite, but softer than feldspar.

In conclusion, the tests show that the mineral in question is a fluorite.

Answer:

They are good electrolytes

Complete Question

A guest orders a drink that contains 4 1/2 ounces of 80-proof liquor. Approximately how many drinks does this beverage contain?

Answer:

[tex]No\ of\ drinks =3[/tex]

Explanation:

From the question we are told that:

Ordered drink 4 1/2 ounces of 80-proof liquor

Generally

80-proof liquor contains 40\% alcohol

Giving the drink a standard 1.5 ounce of distilled spirit

Therefore

[tex]No\ of\ drinks =\frac{4.5}{1.5}[/tex]

[tex]No\ of\ drinks =3[/tex]

Answer:

AgNo3+Mgcl2--->Agcl2+Mg(No3)2

I hope this helps

Explanation:

2Fe (s) + 3Cl2 (g) = 2FeCl3 (s)

Answer:

linear

Explanation:

Actually I consulted various sources too and that was the most sought answer,I just decided to answer you before studying it too

Answer:

The FitnessGram™ Pacer Test is a multistage aerobic capacity test that progressively gets more difficult as it continues. The 20 meter pacer test will begin in 30 seconds. Line up at the start. The running speed starts slowly, but gets faster each minute after you hear this signal. [beep] A single lap should be completed each time you hear this sound. [ding] Remember to run in a straight line, and run as long as possible. The second time you fail to complete a lap before the sound, your test is over.

Answer:

neutrons should be added with the protons

hydrated cucl2 have blue-green colour

here's the answer to your question

The relative mass of the magnesium oxide (MgO) is equal to 40 g. The percentage by mass of magnesium in MgO is 60 %.

The mass percentage of any element in a particular compound can be calculated from the number of parts by mass of the element in 100 parts by mass of a given compound.

Calculate the molar mass of the given compound by adding the atomic masses of the present elements. Then, the percentage of each element can be determined by dividing the total mass of the element by the molar mass of the compound multiplied by 100.

Given, the molecular formula of magnesium oxide is MgO. The atomic mass of Mg and O is 24 g and 16 g respectively.

The relative formula mass of the MgO = 40 g/mol

The mass percentage of the Mg = (24/40) × 100 = 60 %

Therefore, the mass percentage of the Mg in MgO is equal to 60 %.

Learn more about  the mass percentage, here:

brainly.com/question/16750428

#SPJ2

The answer is C. 5

Hope I helped

I guess ensuring that you don't suck the insects or specimen collected by ensuring there is a net in the pooter

Answer: A reaction element are those elements that can take part in a chemical reaction.

Explanation:

An element is made up of atoms that has the same atomic number. It is the basic material of which all matter is composed of. These elements cannot be broken down further into smaller substances by any chemical reaction. Each element has a unique number of protons in its atom. For example,

--> a hydrogen atom has 1 proton,

--> a Helium atom has 2 protons,

--> a Lithium atom has 3 protons, and

--> a carbon atom has 6 protons.

A chemical reaction on the other hand involves rearrangement of the constituent atoms of reactants to create different substances as products. The bonds between atoms are either broken or created to form new molecules. There are different types of chemical reaction which includes:

--> Decomposition reaction

--> Neutralization reaction

--> single displacement reaction and

--> combustion reaction.

Answer:

D- Release of dust during volcanic eruption

Explanation:

During major explosive eruptions huge amounts of volcanic gas, aerosol droplets, and ash are injected into the stratosphere. Injected ash falls rapidly from the stratosphere -- most of it is removed within several days to weeks -- and has little impact on climate change. But volcanic gases like sulfur dioxide can cause global cooling, while volcanic carbon dioxide, a greenhouse gas, has the potential to promote global warming.

answer:

a - decrease in the suns energy.

explanation:

although the other options do discuss climate, temperature, etc., the sun DIRECTLY influences the earth's climate and would most likely affect it on a larger scale. for example, warm and cold ocean currents would affect the temperature of the ocean and could touch bay cities or islands, but they would not dictate the overall climate of the earth :)

♡ hopefully my reply helped you come to an answer~ please keep in mind that my response is purely that... MY response! i still have lots to learn, so please correct/educate me if you have found otherwise ♡

Answer: 52.17%

Explanation:

Number of matches in the box = 46

Number of matches that lit on the first strike = 22

Number of matches that did not light on the first strike = 46 - 22 = 24

Therefore, the percentage of the matches in the box did not light on the first strike will be:

= (Number of matches that did not light on the first strike / Number of matches in the box) × 100

= 24/46 × 100

= 52.17%

Therefore, the percentage of the matches in the box that did not light on the first strike is 52.17%.

Answer:

Letter b so F

Explanation:

I hope this help

Explanation:

All five ions have an equal number of electrons and therefore share the same electron configuration. For example, a neutral calcium atom (Z=20) has 20 electrons; it loses two of them to form a Ca2+ cation, which would thus contain 20−2=18 electrons. Similarly, a phosphorus atom (Z=15) gains three electrons to form a P3− anion that contains 15+3=18 electrons.

Positively-charged protons in the nuclei attract the negatively-charged electron cloud. Each proton carries a +1 charge; the more protons an atom or ion contains the stronger the attraction it poses on its electron cloud. A nucleus of strong positive charge pulls its electron cloud towards itself tightly such that the latter would have a small radius.

The periodic table is arranged in the order of increasing proton number. Phosphorus comes the first among the five species and contains the least number of protons. Its ion would be the largest among the five. Calcium comes the last and forms the smallest ion.

Number of protons per nucleus P<S<Cl<K<CaStrength of Electrostatic attraction on the electron cloud P<S<Cl<K<CaIonic radius P3−>S2−>Cl−>K+>Ca2+

Answer:

Reducing sugars are sugars where the anomeric carbon has an OH group attached that can reduce other compounds. Non-reducing sugars do not have an OH group attached to the anomeric carbon so they cannot reduce other compounds. ... Maltose and lactose are reducing sugars, while sucrose is a non-reducing sugar

Answer:

[tex]\boxed {\boxed {\sf A. \ 186.94 \ L}}[/tex]

Explanation:

We are asked to find the original volume of a gas given a change in temperature. Since pressure remains constant, we are only concerned with volume and temperature, so we use Charles's Law. This states the volume of a gas is directly proportional to the temperature. The formula for this law is:

[tex]\frac {V_1}{T_1}= \frac{V_2}{T_2}[/tex]

The gas begins with a temperature of 450 Kelvin, but the volume is unknown.

[tex]\frac {V_1}{450 \ K }= \frac{V_2}{T_2}[/tex]

The gas is cooled to 248.9 Kelvin and the gas occupies a volume of 103.4 liters.

[tex]\frac {V_1}{450 \ K }= \frac{103.4 \ L}{248.9 \ K}[/tex]

Since we are solving for the original volume, we must isolate the variable V₁. It is being divided by 450 Kelvin. The inverse operation of division is multiplication, so we multiply both sides of the equation by 450 K.

[tex]450 \ K \frac {V_1}{450 \ K }= \frac{103.4 \ L}{248.9 \ K}* 450 \ K[/tex]

[tex]V_1= \frac{103.4 \ L}{248.9 \ K}* 450 \ K[/tex]

The units of Kelvin cancel.

[tex]V_1= \frac{103.4 \ L}{248.9 }* 450[/tex]

[tex]V_1= 0.4154278827 \ L *450[/tex]

[tex]V_1= 186.9425472 \ L[/tex]

Round to the nearest hundredth. The 2 in the thousandths place tells us to leave the 4 in the hundredth place.

[tex]V_1 \approx 186.94 \ L[/tex]

The original volume is approximately 186.94 liters and Choice A is correct.

Answer:

- 10.6° C

Explanation:

Given that,

In the aqueous sucrose solution,

Molality of the solution (m) = 5.7

Freezing point constant (K) = 1.86

To find,

The freezing point of the solution = ?

Method:

To find its freezing point, we will first find out if the solute demonstrates an electrolyte or not.

In case it is not, the van't Hoff factor i.e. ration of particles' concentration denoted by (i) would be taken as 1. So,

ΔT(change in temperature) = i * m * K              (putting the given values)

= 1 * 5.7 * 1.86

= 10.6° C

Thus, the freezing point equals to 0 - 10.6° C = -10.6° C.

Answer:

okay so basically what you are being tested is if you know the difference between simple and fractional distillation and okay you can evaporate the mixture but you won't obtain water so you will use simple distillation to obtain both salt and water

Answer:

There are 24*60 minutes in a day (ignoring the imperfections of the natural world, the Earth and Sun). So there are 24*60 valid 24 hour times (excluding seconds) on a digital clock.

A measure of time representing the interval between consecutive passages of the Sun across the meridian, averaged over one year. 1 day = 24 hr (86,400 sec) and 60 minutes.

hope it helps ya mate! :-P

Answer:

Gases expand the most upon heating because the intermolecular space is more than in solids or liquids.

Explanation:

hopes it helps

Exothermic reaction is where there is release of energy during a reaction

The enthalpy of exothermic reaction is negative

The relation between energy of products, reactants and enthalpy of reaction is

Enthalpy of reaction =  sum of enthalpy of formation of products - sum of enthalpy of formation of reactants .

As enthalpy of reaction is negative, it means the enthalpy of products is less than the enthalpy of reactants  so answer is :

In an exothermic reaction the energy of the product is less than the energy of the reactants.

C.

An endothermic reaction is a reaction that absorbs heat from the surroundings. That means that the energy of the system must increase. Therefore, the answer must be C as the products should have higher energy than the reactants.