Need help on 1-10. for chemistry

In an endothermic reaction would energy be considered a reactant or a product?

timurjin [86]

Answer:

In an endothermic reaction, the products have more stored chemical energy than the reactants. In an exothermic reaction, the opposite is true. The products have less stored chemical energy than the reactants. The excess energy in the reactants is released to the surroundings

4 0

3 years ago

Over a long period of time, an igneous rock changes into a sedimentary rock. Which of these actions must have affected the igneo

Alla [95]

Answer: The actions that must have affected the igneous rock in order to form the sedimentary rock is that (It must have been broken down into sediments).

Explanation:

Rocks are solid structures that occurs naturally which is made up of different minerals. There are three main types of rocks, these includes:

--> METAMORPHIC ROCKS: These are the type of rocks which are formed by temperature and pressure changes inside the Earth.

--> SEDIMENTARY ROCKS: these rocks are usually formed from pre-existing rocks through the process of weathering (breaking down) of rocks.

--> IGNEOUS ROCKS: these rocks are formed when molten magma cools beneath or above the earth surface.

The actions that must have affected the igneous rock in order to form the sedimentary rock is that the igneous rocks are broken down into smaller pieces by erosion and weathering processes. Sediments which are formed accumulates at the earth surface. Over a long period of time, these sediments builds successive layers on top of one another. The sediments near the base hardens to form sedimentary rocks. This justifies the statement as a correct option (It must have been broken down into sediments).

3 0

3 years ago

Molecules have ionization energies, just like atoms do. The ionization energy for molecular oxygen, for example, is 1314 kJ/mol.

taurus [48]

Answer:

91.1835 nm

Explanation:

Given that the ionization energy of the oxygen molecule = 1314 kJ/mol

It means that

1 mole of oxygen molecules can be ionized by the energy = 1314 kJ = 1314000 J

1 mole of molecules contains 6.022 × 10²³ atoms

So,

6.022 × 10²³ atoms of oxygen molecules can be ionized by the energy = 1314000 J

1 atom require $\frac{1314000}{6.022\times 10^{23}}\ J$ of energy

Energy = $2.18\times 10^{-18}\ J$

Also

$E=\frac {h\times c}{\lambda}$

Where,

h is Plank's constant having value $6.626\times 10^{-34}\ Js$

c is the speed of light having value $3\times 10^8\ m/s$

$\lambda$ is the wavelength

So,

$\lambda=\frac {h\times c}{E}$

$\lambda=\frac{6.626\times 10^{-34}\times 3\times 10^8}{2.18\times 10^{-18}}\ m$

$\lambda=91.1835\times 10^{-9}}\ m$

Also,

$1\ nm=10^{-9}}\ m$

So, wavelength = 91.1835 nm

6 0

3 years ago

An element has five isotopes. Calculate the atomic mass of this element using the information below. Show all your work. Using t

Katena32 [7]

Answer: Sol:-

Data provided in the question is :-

Atomic mass of isotope -1 = 64 amu

Atomic mass of isotope -2 = 66 amu

Atomic mass of isotope -3 = 67 amu

Atomic mass of isotope -4 = 68 amu

Atomic mass of isotope - 5 = 70 amu

Percentage abundace of isotope - 1 = 48.89 %

Percentage abundance of isotope -2 = 27.81 %

Percentage abundance of isotope - 3 = 4.11%

Percentage abundance of isotope-4 = 18.57%

Percentage abundance of isotope - 5 = 0.62 %

Formula used :-

Average atomic mass of an element =[ {(atomic mass of isotope-1 * percentage abundance of isotope-1) + ( atomic mass of isotope-2 * percentage abundance of isotope -2) + ( atomic mass of isotope -3 * percantege abundance of isotope-3 ) + ( atomic mass of isotope-4 * percentage abundance of isotope-4) + (atomic mass of isotope-5 * percentage abundance of isotope-5)} / 100]

Calculation :-

Put all the value in the formula :-

Average atomic mass of an element = [{(64 * 48.89) + (66 * 27.81) + (67 * 4.11) + (68 * 18.57) + (70 * 0.62)} / 100] amu

= [{(3128.96) + (1835.46) +(257.37) + (1262.76) + (43.4)} / 100] amu

= {(6528.04) / 100} amu

= 65.2804 amu

Average atomic mass of an element is = 65.2804 amu

Then this mass is approximatly equal to atomic mass of zinc so this element would be zinc

atomic mass of zinc = 65.38 \approx 65.2804 amu

5 0

3 years ago

how much energy must be released by 50.0 g of steam to decrease its temperature from 125.0 degrees Celsius to 100.0 degrees Cels

REY [17]

Answer:

5250 Joules

Explanation:

Mass = 50g

Initial Temperature = 125.0 degrees Celsius

Final Temperature = 100 degrees Celsius

Temperature change = Final - Initial = 100 - 125 = -25

Heat = ?

These quantities are related by the equation;

H = mCΔT

where c = specific hear capacity = 4.2 J/g°C

H = 50 * 4.2 * (-25)

H = -5250 J (The negative sign is because heat is being released)

7 0

3 years ago