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
Dahasolnce [82]
3 years ago
7

What is the universe made of? Astronomers face an embarrassing conundrum: they don't know what 95% of the universe is made of.

Chemistry
1 answer:
Citrus2011 [14]3 years ago
4 0

Answer:

I think u understand this answers

You might be interested in
Why was mass lost from the crucible during the reaction?
Alexxandr [17]
If the crucible wasn't covered with a lid the reactants may have produced a gas that was released into the surroundings, or mass may have been lost in the form of water vapour.
6 0
3 years ago
A compound is found to have 55.7% hafnium+and+44.3%+chlorine.+what+is+the+empirical+formula?
uranmaximum [27]

The empirical formula of a compound found to have 55.7% hafnium and 44.3% chlorine is HfCl4.

<h3>How to calculate empirical formula?</h3>

The empirical formula of a compound is a notation indicating the ratios of the various elements present in a compound, without regard to the actual numbers.

The empirical formula of the given compound can be calculated as follows:

  • Hafnium = 55.7% = 55.7g
  • Chlorine = 44.3% = 44.3g

First, we convert mass values to moles by dividing by the molar mass of each element

  • Hafnium = 55.7g ÷ 178.49g/mol = 0.312mol
  • Chlorine = 44.3g ÷ 35.5g/mol = 1.25mol

Next, we divide each mole value by the smallest

  • Hafnium = 0.312 ÷ 0.312 = 1
  • Chlorine = 1.25 ÷ 0.312 = 4

Therefore, the empirical formula of a compound found to have 55.7% hafnium and 44.3% chlorine is HfCl4.

Learn more about empirical formula at: brainly.com/question/14044066

#SPJ1

7 0
1 year ago
How much time will it take a car traveling at an average of 75 mph to go a distance of 225 miles​
mojhsa [17]

Time taken = 3 hours

<h3>Further explanation</h3>

Given

speed : 75 mph

distance : 225 miles

Required

time taken

Solution

An equation of constant velocity motion  

\large {\boxed {\bold {d = v \times \: t}}}

d = distance = m  

v = speed = m / s  

t = time = seconds  

Input the value :

t = d : v

t = 225 miles : 75 miles/hour

t = 3 hours

7 0
3 years ago
0.00121 mol to grams
Gwar [14]

Answer: I believe the answer you are looking for is 0.02180

7 0
3 years ago
What is the enthalpy of fusion of water?
malfutka [58]

Answer:

d-  334 kJ/g.

Explanation:

You can detect it from the units of the different choices.

a- has the unit J/g.°C that is the unit of the specific heat capacity (c).

b- has the unit Kelvin that is the unit of temperature.

c- has the unit g/mol which is the unit of the molar mass.

d- has the unit kJ/g which is the unit of the enthalpy divided by the no. of rams that is the specific entha;py of fusion.

<em>So, the right choice is: d-  334 kJ/g.</em>

5 0
3 years ago
Other questions:
  • To your unknown you add HCl to precipitate the Group A ions (Ag and Hg). This precipitate is removed and NH3 is added to it to r
    10·1 answer
  • From the following enthalpy of reaction data and data in Appendix C, calculate ΔH∘f for CaC2(s): CaC2(s)+2H2O(l)→Ca(OH)2(s)+C2H2
    13·1 answer
  • 1. A sample of gas has an initial volume of 25 L and an initial pressure of 123.5 kPa. If the pressure changes to
    9·1 answer
  • Economics is about the production of goods and services which requires that allocation of what
    8·1 answer
  • Two teaspoons of salt are added to a glass of water which is then stirred until no more salt grains can be seen. Two more teaspo
    9·2 answers
  • what is the correct definition of refraction? 1. A change in the direction of light when it goes from one medium into a differen
    8·2 answers
  • The weight of the body in the air is .... the weight of the submerged body
    15·1 answer
  • Consider the model of a sodium atom. An orange circle labeled upper N a is surrounded by three concentric circles. The innermost
    12·2 answers
  • Please help asap!!!!!!!!!!!
    5·1 answer
  • Carbon-14 can be used to date remains as far back as ____________.
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!