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
Zigmanuir [339]
3 years ago
5

This one is actually 30 points chem quesitons

Chemistry
1 answer:
GuDViN [60]3 years ago
5 0

Answer:

The answers to your questions are below:

Explanation:

Question 31 Silicon and sulphur, because they are in the same period (3)

Question 34 the third option, density is not in the table

Question 37 group 1A alkali metals

Question 38 group 1A, oxygen group

Question 39 They are metalloids

You might be interested in
How do the cells in your body get energy?
Anastasy [175]
The cells get into your body by the lungs this answer is correct cause i had the same question and my teacher mark it correct
4 0
3 years ago
Determine the molality of a solution of methanol dissolved in ethanol for which the mole fraction of methanol is 0.135. Give you
Alja [10]

<u>Answer:</u> The molality of the solution is 0.11 m

<u>Explanation:</u>

We are given:

Mole fraction of methanol = 0.135

This means that 0.135 moles of methanol is present in 1 mole of a solution

Moles of ethanol = 1 - 0.135 = 0.865 moles

To calculate the mass for given number of moles, we use the equation:

\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}

Moles of ethanol = 0.865 moles

Molar mass of ethanol = 46 g/mol

0.865mol=\frac{\text{Mass of ethanol}}{46g/mol}\\\\\text{Mass of ethanol}=(0.865mol\times 46g/mol}=39.79g

To calculate the molality of solution, we use the equation:

Molality=\frac{m_{solute}\times 1000}{M_{solute}\times W_{solvent}\text{ (in grams)}}

Where,

m_{solute} = Given mass of solute (methanol) = 0.135 g

M_{solute} = Molar mass of solute (methanol) = 32 g/mol

W_{solvent} = Mass of solvent (ethanol) = 39.79 g

Putting values in above equation, we get:

\text{Molality of methanol}=\frac{0.135\times 1000}{32\times 39.79}\\\\\text{Molality of methanol}=0.106m\approx 0.11m

Hence, the molality of the solution is 0.11 m

6 0
3 years ago
Law of conservation of mass to explain why a chemical equation must be balanced?
SOVA2 [1]
Chemical equations must always balance due to the principles outlined in The Law Of Conservation of Matter. This scientific law states that matter cannot be created out of nothing nor can it be destroyed.
7 0
3 years ago
Read 2 more answers
What are the major parts of the ecosystem
eduard

Answer:

Ecosystems have lots of different living organisms that interact with each other. The living organisms in an ecosystem can be divided into three categories: producers, consumers and decomposers. They are all important parts of an ecosystem. Producers are the green plants.

Explanation:

Hope this helps

4 0
3 years ago
An ideal gas in a sealed container has an initial volume of 2.80 L. At constant pressure, it is cooled to 18.00 °C, where its
Aleks04 [339]

Answer:

T_1=-91.18\°C

Explanation:

Hello there!

In this case, given the T-V variation, we understand it is possible to apply the Charles' law as shown below:

\frac{T_1}{V_1}= \frac{T_2}{V_2}

Thus, since we are interested in the initial temperature, we can solve for T1, plug in the volumes and use T2 in kelvins:

T_1= \frac{T_2V_1}{V_2}\\\\T_1= \frac{(18.00+273.15)K(1.75L)}{(2.80L)}\\\\T_1=182K-273.15\\\\T_1=-91.18\°C

Best regards!

6 0
3 years ago
Other questions:
  • How are elements similar to those in the same group on the periodic table ​
    12·1 answer
  • What monatomic ions would you expect potassium (Z = 19) and bromine (Z = 35) to form?
    11·1 answer
  • In 1928, 47.5 g of a new element was isolated from 660 kg of the ore molybdenite. the percent by mass of this element in the ore
    9·2 answers
  • A sample of gas is held at 100oc at a volume of 20 L.if the volume is increased to 40 L what is the new temperature of the gas i
    14·1 answer
  • which describes an object’s speed in free fall? the object accelerates until it reaches its terminal velocity. the object falls
    5·2 answers
  • How does distance affect the strength of the force of gravity
    9·1 answer
  • Why is a lot of energy needed to break covalent bonds
    14·1 answer
  • How many moles of helium are 8.84×10^24 atoms of He?
    9·1 answer
  • 2. During asexual reproduction in paramecia, a single paramecium becomes two new
    10·1 answer
  • What is Sublimation!?​
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!