Can you guys help!!!

During a certain chemical reaction, the temperature gradually increases.
Which statement best describes this process?
A. It is combustion.
B. It is endothermic.
C. It is a closed system.
D. It is exothermic.

No links!!!
No spams!!​

Answers

Answer 1

Answer:

D. lt is exothermic is the correct ans


Related Questions

If I have 0.294L of a 2.OM NaOH solution, what will be the concentration if I add 1.824L to the solution?

Answers

Answer:

0.32M

Explanation:

Using the following formula;

CaVa = CbVb

Where;

Ca = concentration of acid (M)

Cb = concentration of bass (M)

Va = volume of acid (HCl)

Vb = volume of base (NaOH)

According to this question, the following were given:

Ca = ?

Cb = 2M

Va = 1.824L

Vb = 0.294L

Using CaVa = CbVb

Ca × 1.824 = 0.294 × 2

1.824Ca = 0.588

Ca = 0.588 ÷ 1.824

Ca = 0.32M

2. Measure the length of a page in centimeters to the nearest tenth of a centimeter with the metric edge of a ruler. Note that nine lines divide the space between each centimeter into 10 millimeters.
The page is ____27.5____ cm long

Answers

58

Explanation:

ccause that is how long it is

A hot metal plate at 150°C has been placed in air at room temperature. Which event would most likely take place over the next few minutes? Molecules in both the metal and the surrounding air will start moving at lower speeds. Molecules in both the metal and the surrounding air will start moving at higher speeds. The air molecules that are surrounding the metal will slow down, and the molecules in the metal will speed up. The air molecules that are surrounding the metal will speed up, and the molecules in the metal will slow down.

Answers

Answer:

last option is correct.

Air molecules surrounding the metal will speed up and metal molecules will slow down

Explanation:

the metal cools when placed in room temperature air which causes surrounding air to heat up.

the speed of molecules slow down for any material which cools and molecules speed increases when any material heats up

The atoms of elements A (blue) and B (orange) form 2 compounds shown here. Do these compounds obey the law of multiple proportions?

Answers

Hello. You have not presented the image that presents the two elements mentioned in the question. This makes it impossible for your question to be answered. However, I will try to help you as best I can.

To say whether the compounds obey the law of multiple proportions, you should observe whether one of the elements, formed from the compounds, maintains a fixed mass, while the other element presents the mass in a varied amount of small, whole numbers, spread across the formed compounds .

This is because the law of multiple proportions states that an element must have a fixed mass when reacting with another element to create compounds. This reaction will allow this element to keep the mass fixed, while the other element will generate different compounds, where each one presents a part of the mass of the forming element, in small and whole numbers.

Can someone please help me!!

Answers

Explanation:

Corrections

- It should be 45 bromine atoms

- Bromine isn't found abundantly as atoms, rather as diatomic molecules

[tex]Br_2[/tex]

Before should show 2 phosphorus atom and 3 bromine molecules to form 2 phosphorus tribromide

The bond is covalent because both bromine and phosphorus is a non-metal

what is a metal ore?​

Answers

Answer:

metal ores are naturally occurring rocks that contain metals or metal compounds in sufficient amounts to make it worthwhile extracting them

How do protons and neutrons stay together in a nucleus?
A Electrostatic forces hold them together
B. Gravitational forces hold them together
C Weak nuclear forces hold them together
D. Strong nuclear forces hold them together

Answers

Answer:

strong nuclear forces that hold them together

any of ya'll good at chemistry?????​

Answers

Answer:

i good at chemistry

Explanation:

not all but i try

In a solution containing 21.2 g sodium carbonate in 1.50 L of solution, calculate
the concentration of the sodium and carbonate ions.

Answers

Answer:

0.13 molL-1

Explanation:

We must first obtain the number of moles of sodium carbonate as follows;

Number of moles = mass/molar mass

Number of moles = 21.2 g/106 g/mol

Number of moles= 0.2 moles

Number of moles = concentration × volume

Volume = 1.50 L

Concentration = number of moles/volume

Concentration = 0.2 moles/1.5 L

Concentration = 0.13 molL-1

why is baking powder a substance

Answers

Answer:

Baking powder is a dry chemical leavening agent, a mixture of a carbonate or bicarbonate and a weak acid. Because carbon dioxide is released at a faster rate through the acid-base reaction than through fermentation.

Baking powder is a mixture because it contains both sodium hydrogen phosphate and potassium hydrogen tartrate (two different compounds.)

How many moles are in 3.45 g of Na2O?Round your answer to three significant
figures. IN A FINAL EXAM HURRY PLEASE

Answers

Answer: There are 0.056 moles present in 3.45 g of [tex]Na_{2}O[/tex].

Explanation:

Given : Mass = 3.45 g

Moles is the mass of substance divided by its molar mass.

Hence, moles of [tex]Na_{2}O[/tex] (molar mass = 61.98 g/mol) is as follows.

[tex]Moles = \frac{mass}{molar mass}\\= \frac{3.45 g}{61.98 g/mol}\\= 0.056 mol[/tex]

Thus, we can conclude that there are 0.056 moles present in 3.45 g of [tex]Na_{2}O[/tex].

According to the Law of Conservation of Mass, the total
moles of reactants in a balanced chemical equation is...?
O always equal to the total moles of the products.
sometimes more or sometimes less than the total moles of the products.
O always more than the total moles of the products.
O always less than the total moles of the products.

Answers

Answer:

Always equal to the total moles of the products.

Explanation:

The law of conservation of mass states that mass in an isolated system is neither created nor destroyed by chemical reactions or physical transformations. According to the law of conservation of mass, the mass of the products in a chemical reaction equal to the mass of the reactants.

Most terrestrial plants are members of this Division:

Bryophyta

Angiosperms

Pinophyta

Pteridophyta

Answers

Answer:

most flowering plants are classified as angiosperms

Answer:

I think the answer is Bryophyta

Explanation:

seedless,non vascular plants that are the closest extant relative of early terrestrial plants

whats the net ionic and total ionic equations? include the ions and states pls:
NiCl2 + Na2CO3 = 2NaCl + NiCO3

Answers

Answer:

Total ionic equation = Ni²⁺ + 2Cl⁻¹ + 2Na⁺ + CO₃⁻² → 2Na⁺ + 2Cl⁻¹ + NiCO₃ (s)

Net ionic equation = Ni²⁺ + CO₃⁻² → NiCO₃ (s)

NiCl₂ (aq) + Na₂CO₃ (aq) → 2NaCl (aq) + NiCO₃ (s)

First, we'll need to expand the complete chemical equation into a total ionic equation (to determine whether a chemical is aqueous or solid, use a solubility chart until the rules are memorized).

Ni²⁺ + 2Cl⁻¹ + 2Na⁺ + CO₃⁻² → 2Na⁺ + 2Cl⁻¹ + NiCO₃ (s)

Now, using the total ionic equation, we can find the net ionic equation. In order to do this, we need to cancel out the aqueous solutions that don't form into solids, as they are extraneous.

Ni²⁺ + 2Cl⁻¹ + 2Na⁺ + CO₃⁻² → 2Na⁺ + 2Cl⁻¹ + NiCO₃ (s)

Ni²⁺ + CO₃⁻² → NiCO₃ (s)

I hope this helped!

Under what conditions is AG for a reaction always positive?

Answers

When H is positive and S is negative

Give me formula for
1)Aluminium chloride
2) Copper sulphate
3) Zinc Nitrate
3) Ammonium Carbonate​

Answers

Answer:

1. AlCl₃

2. CuSO4

3. Zn(NO₃)₂

4. (NH4)2CO3

AlCl₃

CuSO₄

Zn(NO₃)₂

(NH₄)₂CO₃


Will these magnets attract or repel?
Attract
Repel

Answers

Answer:

repel, if you stick them together as they are, because the north and south poles are next to each other

Explanation:

They will repel because north are south is close

Please help .. I’m really stuck

Answers

Answer:

See explanation

Explanation:

pOH = -log[OH^-]

pOH =-log[1×10^-4 molL-1]

pOH = 4

pH +pOH =14

pH = 14 -4

pH =11

b) pOH = -log[OH^-]

pOH =-log[4.9×10^-2molL-1]

pOH = 1.31

pH +pOH =14

pH = 14 -1.31

pH =12.69

c)

pH= -log[H^+]

[H^+] = Antilog [-pH]

[H^+] = Antilog [-3]

[H^+] = 1 × 10^-3 molL-1

d) pOH = -log[OH^-]

[OH^-] = Antilog[-pOH]

[OH^-] = Antilog[-10.4]

[OH^-] = 3.98 ×10^-11

[OH^-] [H^+] = 1 × 10^-14

[H^+] = 1 × 10^-14/3.98 ×10^-11

[H^+] =2.5 ×10^-4 MolL^-1

e) A solution of pH 9 is basic because the pH scale is calibrated in such as way that 0-6.9 is acidic, 7 is neutral and 8 - 14 is basic.

f)

[H^+] = number of moles/volume

[H^+] = 0.35 moles/8L

[H^+] = 0.044 MolL^-1

pH = - log [H^+]

pH = -log [0.044 MolL^-1]

pH= 1.36

If 9.9L of helium are in a tire at 303k,how many liters will be present at 403k if the pressure is held constant.

Answers

Answer:

Final volume, V2 = 13.18 Liters

Explanation:

Given the following data;

Initial volume = 9.9 L

Initial temperature = 303 K

Final temperature = 403 K

To find the final volume, we would use Charles law;

Charles states that when the pressure of an ideal gas is kept constant, the volume of the gas is directly proportional to the absolute temperature of the gas.

Mathematically, Charles' law is given by the formula;

[tex] VT = K[/tex]

[tex] \frac{V_{1}}{T_{1}} = \frac{V_{2}}{T_{2}}[/tex]

Where;

V1 and V2 represents the initial and final volumes respectively.T1 and T2 represents the initial and final temperatures respectively.

[tex] \frac{V1}{T1} = \frac{V2}{T2}[/tex]

Making V2 as the subject formula, we have;

[tex] V_{2}= \frac{V1}{T1} * T_{2}[/tex]

[tex] V_{2}= \frac{9.9}{303} * 403 [/tex]

[tex] V_{2}= 0.0327 * 403 [/tex]

Final volume, V2 = 13.18 Liters

Which properties make a metal a good material to use for electrical wires?

Answers

Answer: it has 2 characteristics and they are conductivity and ductility

Explanation:

The conductivity makes them great conductors of electricity

Answer:

It's B guaranteed;)

Conductivity and ductility

Which diagram shows a pair of electrons that have opposite spins?
O1
1
个个

Answers

Answer:

the answer is half arrow

1. What is the volume of 4.00g of aluminum at STP?

Answers

Answer:

22.4cm³

Explanation:

Avogadro's law shows that Avogadro's volume is 22.4

Please somone help me with a chemistry question brainliest to whoever answers correctly and 20 points

Answers

Answer:

258.15 enjoy

Explanation:

Which of the following combinations of compounds will make a buffer when
mixed?
A. HCl and NaOH
B. CH3COOH and NaCH3Coo
C.HCl and NaBr
D. CH3COOH and NHACI

Answers

Answer:

B. CH3COOH and NaCH3COO

Explanation:

CH3COOH and NaCH3COO will make a buffer when mixed.

What is a buffer solution?

Buffer solutions resist a change in pH when small amounts of a strong acid or a strong base are added. A solution of acetic acid and sodium acetate CH3COOH + CH3COONa is an example of a buffer that consists of a weak acid and its salt.

What are buffer solutions and their types?

Buffers are broadly divided into two types – acidic and alkaline buffer solutions. Acidic buffers are solutions that have a pH below 7 and contain a weak acid and one of its salts. For example, a mixture of acetic acid and sodium acetate acts as a buffer solution with a pH of about 4.75.

Learn more about buffer solutions here https://brainly.com/question/8676275

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Which of the following is not a part of every scientific investigation?

Group of answer choices

Collection of relevant empirical evidence

Using models to understand objects and processes better

Use of logical reasoning

Devising hypothesis, making predictions

Answers

Answer:

the correct answer is Group of answer choices

Using models to understand objects and processes better  is not  part of every scientific investigation while collection of relevant empirical evidence,use of logical reasoning and devising hypothesis, making predictions is  a part.

What is hypothesis?

Hypothesis can be defined as an assumption which is made for the sake of argument . It is an interpretation of a practical condition for which action needs to be taken.It is defined as a tentative assumption which is made to test logical consequences.It is an antecedent clause of a statement which is conditional.

It is constructed before research. There are six types of hypothesis 1)simple hypothesis 2) complex hypothesis 3) directional hypothesis 4)non-directional hypothesis 5) null hypothesis 6)casual hypothesis

The hypothesis should be clear and precise, it must be specific and way of explanation of hypothesis should be simple.

Learn more about hypothesis,here:

https://brainly.com/question/29519577

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What value is closest to the mass of the atom ?

Answers

Answer:

mass number

Explanation:

Answer and Explanation: The value closest to the mass of an atom is its mass number. The mass number is the total count of the protons and neutrons in the nucleus of the...

mass number

hope that helped

A block is pulled 0.90 m to the right in 2.4 s. What is the block's average speed to the nearest hundredths of a m/s?

Answers

i just need points sorry

Which gas is produced when a carbonate undergoes thermal decomposition

Answers

Answer:

carbon dioxide gas

Explanation: This type of reaction is called a thermal decomposition. This reaction is very common in where carbon dioxide gas makes Products rise..

Which is the correct Lewis dot structure of NH2-?

Answers

Answer:

A

Explanation:

because it can share and remain with ither electrons

The volume of a gas at 5.00 ATM is 3.5 L what is the volume of the gas at 7.00 ATM at the same temperature

A- 2.5 L
B- 5.0 L
C- 10. L
D- 12 L

Answers

B. 5.0L, i just took the test and got a 100%

Answer:

B) 5.0L

Explanation:

Like the Ford F-150 V8 Cyote 5.0L engine

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