help pls............

Answer:

A. It is exothermic

Explanation:

Combustion is a chemical reaction in which a substance combines with oxygen present in air to produce carbon (iv) oxide and water as well release  heat and light energy.Combustion is an exothermic process.

An exothermic reaction releases energy in the form of heat to the surroundings. The energy required to break bonds in the reactants is less than the energy required to form new bonds in the products in an exothermic reaction.

From the given options;

A. It is exothermic is determinable since the reaction is a combustion reaction

B. The bond making energy is more than 600 kJ is not certain because the mass of the wood being burnt is not given. Also, wood is not composed of a specific element that would be taking part in the reaction, rather it is composed of various substances.

C. It is endothermic. is wrong because combustion of wood is exothermic.

D. The bond breaking energy is more than 600 kJ is not certain because the mass of the wood being burnt is not given. Also, wood is not composed of a specific element that would be taking part in the reaction, rather is composed of many substances.

Answer:

[tex]180^\circ[/tex] by the VSEPR theory.

Explanation:

This question is asking for the bond angle of the [tex]\rm C=C=O[/tex] bond in [tex]\rm H_2C=C=O[/tex]. The VSEPR (valence shell electron pair repulsion) theory could help. Start by considering: how many electron domains are there on the carbon atom between these two bond?

Note that "electron domains" refer to covalent bonds and lone pairs collectively.

For example, in [tex]\rm H_2C=C=O[/tex], the carbon atom at the center of that [tex]\rm C=C=O[/tex] bond has two electron domains:

In VSEPR theory, electron domains around an atom repel each other. As a result, they would spread out (in three dimensions) as far away from each other as possible. When there are only two electron domains around an atom, the two electron domains would form a straight line- with one domain on each side of the central atom. (To visualize, consider the three atoms in this [tex]\rm C=C=O[/tex] bond as three spheres on a stick. The central [tex]\rm C[/tex] atom would be between the other [tex]\rm C[/tex] atom and the [tex]\rm O[/tex] atom.)

This linear geometry corresponds to a bond angle of [tex]180^\circ[/tex].

Answer:

C. If Assertion is true statement but Reason is false.

Explanation:

The burning of magnesium in air produces magnesium oxide as shown by the equation;

2Mg(s) + O2(g) -----> 2MgO(s)

The magnesium oxide solid is recovered as a white ash. This is a typical example of an oxidation reaction which is also a combustion reaction.

The reason has nothing at all to do with the assertion hence the answer given.

Magnesium oxide is basic just like the oxides of other metals and dissolves in water to yield an alkali.

Answer:

Answer:

C. If Assertion is true statement but Reason is false.

Explanation:

The burning of magnesium in air produces magnesium oxide as shown by the equation;

2Mg(s) + O2(g) -----> 2MgO(s)

The magnesium oxide solid is recovered as a white ash. This is a typical example of an oxidation reaction which is also a combustion reaction.

The reason has nothing at all to do with the assertion hence the answer given.

Magnesium oxide is basic just like the oxides of other metals and dissolves in water to yield an alkali.

Explanation:

Answer:

10 kilowatts or 10,000 kw

Explanation:

Power = Force × Velocity

Given that:

Velocity of car is 50 m/s

The force is 200N

The power would be:

P = 200 × 50

P = 10,000 W

Notice that it only reaches watts because of the unit of the velocity is m/s. Standard unit to make Kw is km.

Since:

1 kw = 1000 w

10 kw = 10000 w

Credits to the person below me for correction.

Answer:

10 KW

Explanation:

The speed of the car is 50m/s.

The force of 200N is produced.

Power (W) = Velocity (m/s) × Force (N)

Power (W) = 50 × 200

Power (W) = 10000

1 Nm/s = 1 Watt

The power in Watts is 10000. The question asks for the power in kilowatts.

1 kilowatts = 1000 Watts

10000/1000 = 10 kilowatts

Answer:

Fluorescent luminaire is the assembly that forms a lamp, called a fluorescent tube, and an armature, which contains the accessories necessary for operation. In certain places, only the lamp is known as a luminaire. The lamp is low pressure mercury vapor discharge and is normally used for domestic or industrial lighting. Its advantage over other types of lamps, such as incandescent lamps, is their energy efficiency.

The lamp consists of a thin glass tube lined internally with various compound chemicals called phosphors, although they generally do not contain the chemical element phosphorus and should not be confused with it. Those chemical compounds emit visible light when receiving ultraviolet radiation. The tube also contains a small amount of mercury vapor and an inert gas, usually argon or neon, at a pressure lower than atmospheric pressure. At each end of the tube is a filament ...

Explanation:

Answer:

biomass is renewable

solar is renewable

coal is non-renewable

natural gas is non-renewable

oil is non-renewable

geothermal energy is renewable

Explanation:

The biomass, solar and geothermal are renewable source of energy and coal, natural gas and oil are non renewable source of energy.

Renewable energy is defined as the energy derived from natural source of energy that are replenished at the higher rate then they are consumed.

It can also be defined as the energy that are collected from renewable resources that are replenished on a human time scale.

Solar, wind, tidal, biomass, geothermal etc. are some of the example.

Non renewable energy is defined as the natural resource of energy that cannot be easily replaced by human means at a pace quickly enough to keep up with the consumption.

Coal, petrol, oil, natural gas, fossil fuel etc. are some of the example.

Thus, the  biomass, solar and geothermal are renewable source of energy and coal, natural gas and oil are non renewable source of energy.

To learn more about renewable source, refer to the link below:

https://brainly.com/question/13258110

#SPJ2

Explanation:

Stoichiometry measures these quantitative relationships, and is used to determine the amount of products and reactants that are produced or needed in a given reaction. Describing the quantitative relationships among substances as they participate in chemical reactions is known as reaction stoichiometry.

Answer:

1:1

Explanation:

There is one mole of zinc (Zn) and one mole of zinc sulfate (ZnSO₄).

The mole ratio is 1:1.

Hope this helps.

Answer:

1:1

Explanation:

Energy storage and transport. Chemical energy transport.

Answer:

to clean the water

Explanation:

Answer:

a. 82.68 g b. 9.8 min

Explanation:

a. The amount of gold deposited by 5 A current in 2 hrs 15 mins

Since charge Q = It where I = current = 5 A and time = 2 hrs 15 mins = 2 × 60 min + 15 min = 120 + 15 min = 135 min = 135 × 60 s = 8100 s

Q = 5 A × 8100 s

= 40500 C

Also, Q = nF where n = number of moles of gold deposited and F = Faraday's constant = 96500 C

n = Q/F = 40500 C/96500 C = 0.4195 moles ≅ 0.42 mole

Now n = m/M where m = mass of gold and M = molar mass of gold = 197

m = nM

= 0.42 × 197 g

= 82.68 g

b. The time taken for 6g of gold to be deposited.

We first find the number of moles of gold in 6g of gold

Since n = m/M and m = 6 g

n = 6/197 = 0.0305 mole

Q = It = nF

t = nF/I

= 0.0305 mol × 96500 C/5 A

= 2939.09 mol C

= 587.82 s

Changing t to minutes

587.82/60 s = 9.8 min

Answer:

15000 g

Explanation:

We simply multiply 100 grams with 150 grams to get 1.5(10⁴) grams.

Answer:

0.015 kg2

Explanation:

Answer:

i metal

ii nonmetal

iii metal

iv nonmetal

Explanation:

If you look up what the element of a heater is, you get a picture of some sort of rod. It's the heating element of the heater, and must be some type of metal to conduct electricity and warm up. Fishing rods are made of either fiberglass, graphite, or carbon fibre. These are nonmetals. In order for a lightning rod to conduct electricity and bring the lightning down to the ground, it has to be metal. You wouldn't want a metal oven mitt, as that would burn your hand.

Answer:

Answers are in the explanation

Explanation:

Precision and accuracy are both statistical concepts. Precision is about how close are the measured values to each other. Accuracy is closeness of the measured values to a specific value or reference value.

There are many ways to calculate precision and accuracy, one is stimating precision as Relative Uncertainty and accuracy as Relative Error.

Formulas are:

Relative Uncertainty: Standard desviation /  Measured value.

Relative Error: Measured Value - Expected Value / Expected value

Measured value is the aveage of the values.

For student 1:

Mean = 25

Standard desviation = 1.5275

Relative Uncertainty: 1.5275 /  25

Relative Uncertainty: 0.061

Relative Error: 25 - 20 / 20

Relative Error: 0.25

For student 2:

Mean = 24.5

Standard desviation = 0.5477

Relative Uncertainty: 0.5477 / 24.5

Relative Uncertainty: 0.02

Relative Error: 24.5 - 20 / 20

Relative Error: 0.225

As the student 2 has a low Relative error and uncertainty, you can say student 2 is more accurate and precise

Answer:

1. Acid produces hydrogen ions in a solution.

2. Base produces hydroxide ions in a solution.

Answer:

1. A substance that produces hydrogen ions in solution; alternatively, a proton donor

Acid

2. A substance that produces hydroxide ions in solution; alternatively, a proton acceptor

Base

Answer:

remains constant regardless of the pH

Explanation:

The pH refers to the hydrogen potential or hydrogen power that states the aqueous solution acidity. It varies from 0 to 14. The higher pH values denotes  more basic solutions while on the other hand,  the lower pH values denote more acidic

An acidic solution refers to a solution at which the hydrogen ions concentration is more than the hydroxide ions concentration

Therefore the ion product of water remains constant as the value of both hydrogen ions and hydroxide ions is relatively small as non-dissociated water concentration would remain the same.

Hence, the second option is correct

Answer:

remains constant regardless of the pH

Explanation:

Answer:

B

Explanation:

DuPont created the first acrylic fibers in 1941 and trademarked them under the name Orlon.

Answer:

6^3 I believe.

Explanation:

If it's wrong it may be 6^2 because you should square it, but I think it's 6^3

Answer:

If you know the number of protons and neutrons you have to simply subtract the number of neutrons by number of protons the answer will be number of neutron

Explanation:

Answer:

We can find the amount of electrons through its Atomic number and with the help of electronic configuration

Answer:

Hope this helps you

Answer:

Explanation:

Properties of metals:

1. They have a lustre ( shine )

2. They have a silvery-grey or golden-yellow colour.

3. They conduct heat and electricity.

4. They are ductile ( can be drawn into wires ) .

5.They are malleable ( can be hammered into thin sheets ).

6. They are sonorous ( make a ringing sound when hit ).

Properties of non-metals:

1. They display a variety of colours.

2. They are poor conductors of heat and electricity.

3. They are not lustrous, ductile or malleable.

Hope it helps

plz mark as brainliest!!!!!!

Answer:

time for sulphur dioxide to diffuse is 221.05 secs

The time for sulphur dioxide to diffuse is 108 sec.

Sulfur dioxide has a molecular weight of sixty-four and as a result, the square root is 8. since its inversely proportional, on the way to diffuse two times as fast, the rectangular root of the molecular weight should be 4, and subsequently the molecular weight might be 16. So the solution is methane (CH4).

The charge of diffusion for a gas is inversely proportional to the rectangular root of its molecular mass (Graham's law). The gasoline with the lowest molecular weight will effuse the fastest. The lightest, and consequently fastest, fuel is helium.

Learn more about Sulfur dioxide here: https://brainly.com/question/15654465

#SPJ2

answer:

a)1.274 g b) 0.013 mole

Explanation:

a) Mass of 1 mol of CuSo4. 5H20=

[tex]63 + 32 + (16 \times 4) + (7 \times 1) + (16 \times 5)[/tex]

=246g

no. moles of CuSo4. 5H2O=

[tex] \frac{mass}{mass \: of \: 1mole} [/tex]

so moles

=

[tex] \frac{3.14}{246} [/tex]

0.013 mole

in the equation

1 mole of sulphuric acid reacts to form 1 mole of CuSo4.5H2O

in other words

0.013 mole of sulphuric acid reacts to form 0.013 mole of CuSo4.5H2O

so mass of 1 mole (Mr) H2So4=

[tex](2 \times 1) + 32 + (16 \times 4)[/tex]

98g

mass of sulphuric acid= mole × mass of 1 mole

so mass= 0.013 × 98

1.274 g

b) In the equation

1 mole of sulphuric acid reacts to form 1 mole of copper(ll) oxide

in other words

0.013 mole of sulphuric acid reacts to form 0.013 mole of copper (ll) oxide

so 0.013 mole of copper(ll) oxide is reacted

Hope it helped and pls mark brainliest

Answer:

it becomes poisonous to the body

Answer:

B. The Funnel withe the filter paper.

Explanation:

The next answers is copper and aqueous solution.

The statement, that describes tool was used to collect the solid product of the chemical reaction is "the funnel with the filter paper."

What is a chemical reaction ?

A chemical reaction is a process that converts one or more compounds, known as reactants, into one or more distinct substances, known as products.

Filtration is a basic process for removing solid particles suspended in a liquid solution. Filtration is a method of separating solids from liquids or gases by employing a filter material that enables the fluid but not the solid to pass through. A funnel with filter paper can be used to gather solid product during the filtration process.

Hence the correct answer is the funnel with the filter paper.

Learn more about chemical reaction here

https://brainly.com/question/17053196

#SPJ2

first, we need the molar mass of HNO3(azotic acid) it's equal to 1AH+1AN+3AO(where A is the atomic mass of the element present within the molecule and, it's multiplied by how many times it's present)=1*1+1*14+3*16=15+54=69g/mole

now we multiply the molar mass with the number of moles 69*1.2=82.8 grames

Answer:

transports solid materials

Explanation:

Erosion is a process where solid materials are transported by natural forces such as wind or water.

Answer: c

Explanation:

Answer:

The pressure cooker contains 0.000355 moles of air (to three significant figures).

Explanation:

To find the number of moles of air in the pressure cooker, we can use the ideal gas law.

[tex]PV=nRT[/tex]

where:

Rearrange the equation to solve for n:

[tex]\implies n=\dfrac{PV}{RT}[/tex]

As we have been given the volume in liters, we must first convert it to cubic meters. As 1 liter = 0.001 m³ then 5.68 liters = 0.00568 m³.

Therefore, the values to substitute into the formula are:

Substitute the values into the formula and solve for n:

[tex]\implies n=\dfrac{205 \cdot 0.00568}{8.3144626 \cdot 394}[/tex]

[tex]\implies n=0.000355444...[/tex]

[tex]\implies n=0.000355\; \sf mol\; (3\;s.f.)[/tex]

Therefore, the pressure cooker contains 0.000355 moles of air (to three significant figures).

Answer:

Prokaryotic cells contain DNA, contain ribosomes, and lack a nucleus.

Answer:

Contains DNA

Contains Ribosomes

lacks a nucleus

Explanation: I took the quiz on edge

Answer : The net ionic equation will be,

[tex]H^{+}(aq)+OH^{-}(aq)\rightarrow H_2O(l)[/tex]

Explanation :

In the net ionic equations, we are not include the spectator ions in the equations.

Spectator ions : The ions present on reactant and product side which do not participate in a reactions. The same ions present on both the sides.

The given balanced ionic equation will be,

[tex]HCl(aq)+NH_4OH(aq)\rightarrow NH_4Cl(aq)+H_2O(l)[/tex]

The ionic equation in separated aqueous solution will be,

[tex]H^+(aq)+Cl^-(aq)+NH_4^+(aq)+OH^-(aq)\rightarrow H_2O(l)+NH_4^+(aq)+Cl^-(aq)[/tex]

In this equation, [tex]NH_4^+\text{ and }Cl^-[/tex] are the spectator ions.

By removing the spectator ions from the balanced ionic equation, we get the net ionic equation.

The net ionic equation will be,

[tex]H^{+}(aq)+OH^{-}(aq)\rightarrow H_2O(l)[/tex]

Answer:

75L of additional water to have a pH 1 solution

Explanation:

The reaction of HCl With NaOH is:

HCl + NaOH → H₂O + NaCl

By using molar mass of each reactant you can know how many moles will react, thus:

HCl: 364.6g HCl ₓ (1mol / 36.46g) = 10 moles HCl

NaOH: 80g NaOH ₓ (1mol / 40g) = 2 moles NaOH

That means after the reaction will remain in solution, 10-2 = 8 moles of HCl = 8 moles of H⁺ (In water, HCl dissociates as H⁺ and Cl⁻ ions).

A solution with pH = 1 contains:

pH = -log [H⁺]

1 = -log [H⁺]

0.1M = [H⁺]

As molarity, M is the ratio between moles and liters and you want a solution 0.1M having 8 moles of H⁺ you require:

0.1M = 8 moles H⁺ / 80L

As the student combines the solution with 5L of water, you require