1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Veseljchak [2.6K]
2 years ago
13

What kind of tools did prehistoric people make with flint

Chemistry
1 answer:
barxatty [35]2 years ago
3 0
Spears and knives (Plz thank me if this helped)
You might be interested in
Which type of stoichiometry problems does not require the use of molar mass?
Arlecino [84]

Answer:

Explanation:

It is volume-volume problems that does not require the use of molar mass.

7 0
2 years ago
The enthalpy of vaporization of Bromine is 15.4 kJ/mol. What is the energy change when 80.2 g of Br2 condenses to a liquid at 59
Aleksandr-060686 [28]

The enthalpy of vaporization of Bromine is 15.4 kJ/mol. -7.7 kJ is the energy change when 80.2 g of Br₂ condenses to a liquid at 59.5°C.

<h3>What is Enthalpy of Vaporization ?</h3>

The amount of enthalpy or energy that must be added to a liquid substance into gas substance is called Enthalpy of Vaporization. It is also known as Latent heat of vaporization.

<h3>How to find the energy change from enthalpy of vaporization ?</h3>

To calculate the energy use this expression:

Q = n \Delta H_{\text{vapo.}

where,

Q = Energy change

n = number of moles

\Delta H_{\text{Vapo.}} = Molar enthalpy of vaporization

Now find the number of moles

Number of moles (n) = \frac{\text{Given Mass}}{\text{Molar mass}}

                                   = \frac{80.2\ g }{159.8\ g/mol}

                                   = 0.5 mol

Now put the values in above formula we get

Q = - n \Delta H_{\text{vapo.}         [Negative sign is used because Br₂ condensed here]

   = - (0.5 mol × 15.4 kJ/mol)

   = - 7.7 kJ

Thus from the above conclusion we can say that The enthalpy of vaporization of Bromine is 15.4 kJ/mol. -7.7 kJ is the energy change when 80.2 g of Br₂ condenses to a liquid at 59.5°C.

Learn more about the Enthalpy of Vaporization here: brainly.com/question/13776849

#SPJ1

8 0
1 year ago
A 49.48-mL sample of an ammonia solution is analyzed by titration with HCl. It took 38.73 mL of 0.0952 M HCl to titrate the ammo
Kryger [21]

Answer:

M₂ = 0.0745 M

Explanation:

In case of titration , the following formula can be used -

M₁V₁ = M₂V₂

where ,

M₁ = concentration of acid ,

V₁ = volume of acid ,

M₂ = concentration of base,

V₂ = volume of base .

from , the question ,

M₁ = 0.0952 M

V₁ = 38.73 mL

M₂ = ?

V₂ = 49.48 mL

Using the above formula , the molarity of ammonia , can be calculated as ,

M₁V₁ = M₂V₂  

0.0952 M * 38.73 mL = M₂* 49.48 mL

M₂ = 0.0745 M

8 0
3 years ago
In this reaction, what is the correct coefficient for hydrogen gas? ? h2 + ? o2 ? ? h2o
iragen [17]
To balance a chemical reaction, it is important to remember that the number of atoms of each element in the reactants and the product side should be equal. This is to follows the law of conservation of mass where mass cannot be created or destroyed. So, the total mass that is used to react should have the same value of the total mass of the substances produced from the reactants. The balanced chemical reaction would be written as follows:

<span> 2h2 + o2 = 2h2o

Reactant     =    Product
H = 4           =          4 
O = 2          =           2

Therefore, the correct coefficient for the hydrogen gas would be 2.</span>
6 0
2 years ago
when solid pellets of sodium hydroxide (naoh) dissolve in water, the temperature of the water can rise dramatically. taking naoh
irga5000 [103]

ΔSsys  and ΔSsurr both have values larger than 0.

<h3>Entropy Change: What Is It?</h3>
  • Entropy change is a phenomena that measures the evolution of randomness or disorder in a thermodynamic system.
  • It has to do with how heat or enthalpy is converted during work.
  • More unpredictability in a thermodynamic system indicates high entropy.
  • Heat transport (delta Q) divided by temperature equals the change in entropy (delta S).
<h3>What causes variations in entropy?</h3>
  • When a substance is divided into several pieces, entropy rises.
  • Because the solute particles are split apart when a solution is generated, the dissolving process increases entropy.
  • As the temperature rises, entropy increases.

learn more about entropy change here

brainly.com/question/6364271

#SPJ4

8 0
1 year ago
Other questions:
  • The ratio of carbon atoms to hydrogen atoms to oxygen atoms in a molecule of dicyclohexyl maleate is 4 to 6 to 1. what is its mo
    9·2 answers
  • What is the least amount of energy that can be emitted by an excited electron in a hydrogen atom falling from an excited state d
    5·2 answers
  • Someone help with this please
    9·1 answer
  • How many moles of no2 are equivalent to 74.3g of no2
    14·2 answers
  • A sample of phosphorus-32 has a half-life of 14.28 days. If 55 g of this radioisotope remain unchanged after approximately 57 da
    9·2 answers
  • Jodie is studying the sleeping habits of various types of animals. She wants to know how long each type of animal sleeps during
    7·1 answer
  • Yes456789ghjjjjjjjj<br> uerrehjfkehbfgkbv3kewgvjberdsvbjbedjksbdkjbjkewbkrjbvbrekvbekbvebrkjbv3w
    7·2 answers
  • 6. What do we call Ethene that has been polymerised?​
    11·1 answer
  • If 38 gr of water are produced in reaction, how many mole are CO2 are produced.​
    6·1 answer
  • Mass of 4.50 moles of oxygen gas. Answer with 3 significant digits
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!