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3 years ago

Look at the diagram of the solar system.

Chemistry

2 answers:

arlik [135]3 years ago

8 0

Answer:

Retrograde Motion

Explanation:

Geocentric model of planets was proposed by Ptolemy. It stated that all sun, planets and stars revolve round the earth in circular orbits.

NOTE: Ptolemy: an ancient astronomer, geographer, and mathematician who considered the Earth the center of the universe (the "Ptolemaic system").

vaieri [72.5K]3 years ago

5 0

Answer:

THE ANSWER IS A

Explanation:

Which model is most similar to that of Aristarchus?

The solar system shows the planets in their orbits around the sun in this order: Mercury, Venus, Earth with Moon, Mars, Jupiter, Saturn. Fixed stars are around the outside of the orbit of Saturn.

got it right on edg

PLEASE MARK BRAINLIEST

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C. By examining the physical and chemical properties of evidence at a crime scene, investigators can

OLEGan [10]

Answer:

Physical and chemical properties of evidence can pinpoint the cause of unalive, or can identify the unaliver!

Explanation:

3 0

2 years ago

What mass of hydrogen contains the same number of atoms as 7.00 g of nitrogen

Leto [7]

Molecular mass of nitrogen, N2 = 2*14 = 28
molecular mass of hydrogen, H2=2*1 = 2

Molecules of both elements contain 2 atoms, so the ratio of molecules is the same as the ratio of atoms.

From the molecular masses above,
ratio of number of molecules = ratio of molecular masses, therefore
7g N2 : x g H2 = 28:2
cross multiply:
x=7*2/28=0.5 g of Hydrogen has the same number of atoms as 7 g of nitrogen (at room temperatures)

7 0

3 years ago

Which is the correct net ionic equation for the following reaction: H3PO4 (aq) + 3 LiOH (aq) > Li3PO4 (aq) + 3 H2O (l)?

torisob [31]

Answer: The correct option for the chemical equation $H_3PO_4(aq.)+3LiOH(aq.)\rightarrow Li_3PO_4(aq.)+3H_2O(l)$ is 1.

The correct option for the chemical equation $2HBr(aq.)+Co(OH)_2(aq.)\rightarrow CoBr_2(aq.)+2H_2O(l)$ is 3.

Explanation:

For the chemical equation:

$H_3PO_4(aq.)+3LiOH(aq.)\rightarrow Li_3PO_4(aq.)+3H_2O(l)$

$H_3PO_4$ is a weak acid and hence will not dissociate into ions whereas LiOH is a strong base and will easily dissociate into ions.

The product $Li_3PO_4$ is soluble in water and hence, will dissociate into its respective ions. Hence, the ionic equation for this reaction is:

$H_3PO_4(aq.)+3Li^{3+}(aq.)+3OH^-(aq.)\rightarrow 3Li^{3+}(aq.)+PO_4^{3-}(aq.)+3H_2O(l)$

Net ionic equation becomes:

$H_3PO_4(aq.)+3OH^-(aq.)\rightarrow PO_4^{3-}(aq.)+3H_2O(l)$

So, the correct option is 1.

For the chemical equation:

$2HBr(aq.)+Co(OH)_2(aq.)\rightarrow CoBr_2(aq.)+2H_2O(l)$

HBr and $Co(OH)_2$ are strong acid and strong base respectively, hence they will easily dissociate into ions.

The product, $CoBr_2$ is is soluble in water and hence, will dissociate into its respective ions. Hence, the ionic equation for this reaction is:

$2H^+(aq.)+2Br^-(aq.)+Co^{2+}(aq.)+2OH^-(aq.)\rightarrow Co^{2+}(aq.)+2Br^-(aq.)+H_2O(l)$

The net ionic equation becomes:

$H^+(aq.)+OH^-(aq.)\rightarrow H_2O(l)$

So, the correct option is 3.

4 0

3 years ago

Read 2 more answers

or a particular isomer of C 8 H 18 , the combustion reaction produces 5104.1 kJ of heat per mole of C 8 H 18 ( g ) consumed, und

beks73 [17]

Answer:

The standard enthalpy of formation of this isomer of $C_{8}H_{18}$ is -220.1 kJ/mol.

Explanation:

The given chemical reaction is as follows.

$C_{8}H_{18}(g)+ \frac{25}{2}O_{2}(g) \rightarrow 8CO_{2}(g)+9H_{2}O(g)$

$\Delta H^{o}_{rxn}= -5104.1kJ/mol$

The expression for the entropy change for the reaction is as follows.

$\Delta H^{o}_{rxn}=[8\Delta H^{o}_{f}(CO_{2}) +9\Delta H^{o}_{f}(H_{2}O)]-[\Delta H^{o}_{f}(C_{8}H_{18})+ \frac{25}{2}\Delta H^{o}_{f}(O_{2})]$

$\Delta H^{o}_{f}(H_{2}O)= -241.8kJ/mol$

$\Delta H^{o}_{f}(CO_{2})= -393.5kJ/mol$

$\Delta H^{o}_{f}(O_{2})= 0kJ/mol$

Substitute the all values in the entropy change expression.

$-5104.1kJ/mol=[8(-393.5)+9(-241.8)kJ/mol]-[\Delta H^{o}_{f}(C_{8}H_{18})+ \frac{25}{2}(0)kJ/mol]$

$-5104.1kJ/mol=-5324.2kJ/mol -\Delta H^{o}_{f}(C_{8}H_{18})$

$\Delta H^{o}_{f}(C_{8}H_{18}) =-5324.2kJ/mol +5104.1kJ/mol$

$=-220.1kJ/mol$

Therefore, The standard enthalpy of formation of this isomer of $C_{8}H_{18}$ is -220.1 kJ/mol.

4 0

3 years ago

What is the kinetic energy of a 2kg rabbit hopping at a speed of 1.25 m/s

ICE Princess25 [194]

Answer:

What is the kinetic energy of a 2kg rabbit hopping at a speed of 1.25 m/s?1,5625J

6 0

3 years ago