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
Oxana [17]
3 years ago
13

List three reasons why is the sun essential to our lives on Earth

Chemistry
1 answer:
elena-s [515]3 years ago
5 0

OKAY SO FIRST.... THE SUN IS IMPORTANT FOR PLANTS TO LIVE AND UMMM... SECOND IT PRODUCES LIGHT AND HEAT WHICH WARMS THE EARTH... AND LAST BUT NOT LEAST

You might be interested in
Define Saturated Solution. What happens as a saturates solution cools?
solong [7]

Saturated solution is a solution in which no more solute can be dissolved in the solvent. When saturated solution cools, the solution began precipitate from the solution, because under lower temperature, usually, less amount solute can be dissolved in the solvent.

8 0
3 years ago
Read 2 more answers
A____is a prediction about the outcome of a test or experiment.
Annette [7]

Answer:

hypothesis is the answer

Explanation:

4 0
3 years ago
Read 2 more answers
Excess magnesium reacts with 165.0 grams of hydrochloric acid in a single displacement reaction.
JulsSmile [24]

Answer:

The volume of hydrogen gas produced will be approximately 50.7 liters under STP.

Explanation:

Relative atomic mass data from a modern periodic table:

  • H: 1.008;
  • Cl: 35.45.

Magnesium is a reactive metal. It reacts with hydrochloric acid to produce

  • Hydrogen gas \rm H_2, and
  • Magnesium chloride, which is a salt.

The chemical equation will be something like

\rm ?\;Mg\;(s) + ?\;HCl \;(aq)\to ?\;H_2 \;(g)+ [\text{Formula of the Salt}],

where the coefficients and the formula of the salt are to be found.

To determine the number of moles of \rm H_2 that will be produced, first find the formula of the salt, magnesium chloride.

Magnesium is a group 2 metal. The oxidation state of magnesium in compounds tends to be +2.

On the other hand, the charge on each chloride ion is -1. Each magnesium ion needs to pair up with two chloride ions for the charge to balance in the salt, magnesium chloride. The formula for the salt will be \rm MgCl_2.

\rm ?\;Mg\;(s) + ?\;HCl\;(aq) \to ?\;H_2 \;(g)+ ?\;MgCl_2\;(aq).

Balance the equation. \rm MgCl_2 contains the largest number of atoms among all species in this reaction. Start by setting its coefficient to 1.

\rm ?\;Mg\;(s) + ?\;HCl\;(aq) \to ?\;H_2 \;(g)+ {\bf 1\;MgCl_2}\;(aq).

The number of \rm Mg and \rm Cl atoms shall be the same on both sides. Therefore

\rm {\bf 1\;Mg}\;(s) + {\bf 2\;HCl}\;(aq) \to ?\;H_2 \;(g)+ {1\;\underset{\wedge}{Mg}\underset{\wedge}{Cl_2}}\;(aq).

The number of \rm H atoms shall also conserve. Hence the equation:

\rm {1\;Mg}\;(s) + {2\;\underset{\wedge}{H}Cl}\;(aq) \to {\bf 1\;H_2 \;(g)}+ {1\;MgCl_2}\;(aq).

How many moles of HCl are available?

M(\rm HCl) = 1.008 + 35.45 = 36.458\;g\cdot mol^{-1}.

\displaystyle n({\rm HCl}) = \frac{m(\text{HCl})}{M(\text{HCl})} = \rm \frac{165.0\;g}{36.458\;g\cdot mol^{-1}} = 4.52576\;mol.

How many moles of Hydrogen gas will be produced?

Refer to the balanced chemical equation, the coefficient in front of \rm HCl is 2 while the coefficient in front of \rm H_2 is 1. In other words, it will take two moles of \rm HCl to produce one mole of \rm H_2. \rm 4.52576\;mol of \rm HCl will produce only one half as much \rm H_2.

Alternatively, consider the ratio between the coefficient in front of \rm H_2 and \rm HCl is:

\displaystyle \frac{n(\text{H}_2)}{n(\text{HCl})} = \frac{1}{2}.

\displaystyle n(\text{H}_2) = n(\text{HCl})\cdot \frac{n(\text{H}_2)}{n(\text{HCl})} = \frac{1}{2}\;n(\text{HCl}) = \rm \frac{1}{2}\times 4.52576\;mol = 2.26288\;mol.

What will be the volume of that many hydrogen gas?

One mole of an ideal gas occupies a volume of 22.4 liters under STP (where the pressure is 1 atm.) On certain textbook where STP is defined as \rm 1.00\times 10^{5}\;Pa, that volume will be 22.7 liters.

V(\text{H}_2) = \rm 2.26288\;mol\times 22.4\;L\cdot mol^{-1} = 50.69\; L, or

V(\text{H}_2) = \rm 2.26288\;mol\times 22.7\;L\cdot mol^{-1} = 51.37\; L.

The value "165.0 grams" from the question comes with four significant figures. Keep more significant figures than that in calculations. Round the final result to four significant figures.

5 0
3 years ago
Consider the addition of an electron to the following atoms from the fourth period. Rank the atoms in order from the most negati
lesya [120]

Answer:

Ge: [Ar] 3d10 4s2 4p2 => 6 electrons in the outer shell

Br: [Ar] 3d10 4s2 4p5 => 7 electrons in the outer shell

Kr: [Ar] 3d10 4s2 4p6 => 8 electrons in the outer shell

Explanation:

The electron affinity or propension to attract electrons is given by the electronic configuration. Remember that the most stable configuration is that were the last shell is full, i.e. it has 8 electrons.

The closer an atom is to reach the 8 electrons in the outer shell the bigger the electron affinity.

Of the three elements, Br needs only 1 electron to have 8 electrons in the outer shell, so it has the biggest electron affinity (the least negative).

Ge: needs 2 electrons to have 8 electrons in the outer shell, so it has a smaller (more negative) electron affinity than Br.

Kr, which is a noble gas, has 8 electrons and is not willing to attract more electrons at all, the it has the lowest (more negative) electron affinity of all three to the extension that really the ion is so unstable that it does not make sense to talk about a number for the electron affinity of this atom.

Read more on Brainly.com - brainly.com/question/1832586#readmore

6 0
3 years ago
An object that is already moving can . . .
Yuri [45]
An object that is not already moving will begin to move in the direction of the larger force. An object that is already moving will change its speed and/or its direction.
4 0
3 years ago
Other questions:
  • Explain how chemical change differs from a physical change
    5·2 answers
  • The loss of static energy electric charges move off an object is called
    7·2 answers
  • The closest hominin to a current day human is?
    10·1 answer
  • Which compound contains both ionic and covalent
    6·1 answer
  • The properties of several unknown solids were measured. Solid Melting point Other properties A >1000 °C does not conduct elec
    14·2 answers
  • How many grams of sodium chromate, Na2CrO4, are needed to react completely with
    15·1 answer
  • How many moles of KOH are measured in thisexperiment? See the volume and molarity information given. 2.How many moles of KOH rea
    7·1 answer
  • Both s-cis and s-trans conformers of 1,3-butadiene have a continuous conjugated π system, which of the following statements is t
    6·1 answer
  • What is the temperature of 0.750 mol of a gas stored in a 6,050 mL cylinder al 221 atm?
    5·1 answer
  • Define Electrical Energy.
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!