When the sentence best describes mass movement

denpristay [2]

Answer:

Explanation:

a) In an exothermic reaction, the energy transferred to the surroundings from forming new bonds is ___more____ than the energy needed to break existing bonds.

b) In an endothermic reaction, the energy transferred to the surroundings from forming new bonds is ___less____ than the energy needed to break existing bonds.

c) The energy change of an exothermic reaction has a _____negative_______ sign.

d) The energy change of an endothermic reaction has a ____positive________ sign.

The energy changes occur during the bonds formation and bonds breaking.

There are two types of reaction endothermic and exothermic reaction.

Endothermic reactions:

The type of reactions in which energy is absorbed are called endothermic reactions.

In this type of reaction energy needed to break the bond are higher than the energy released during bond formation.

For example:

C + H₂O → CO + H₂

ΔH = +131 kj/mol

it can be written as,

C + H₂O + 131 kj/mol → CO + H₂

Exothermic reaction:

The type of reactions in which energy is released are called exothermic reactions.

In this type of reaction energy needed to break the bonds are less than the energy released during the bond formation.

For example:

Chemical equation:

C + O₂ → CO₂

ΔH = -393 Kj/mol

it can be written as,

C + O₂ → CO₂ + 393 Kj/mol

5 0

3 years ago

What is a hot spot? ( Must be in your own words) Pleaseeee Hurryy

Ilia_Sergeevich [38]

Answer:

A hot spot is an area on Earth over a mantle plume or an area under the rocky outer layer of Earth, called the crust, where magma is hotter than surrounding magma. The magma plume causes melting and thinning of the rocky crust and widespread volcanic activity.

Hope this is what you mean be hot spot!

I hope this helps you!

Have a great day

7 0

2 years ago

What is the coefficient of Ca(OH)2 in the equation Ca(OH)2 + HNO3 → Ca(NO3)2 + H2O when balanced using the smallest possible coe

Vikentia [17]

Answer:

The coefficient of Ca(OH)2 is 1

Explanation:

Step 1: unbalanced equation

Ca(OH)2 + HNO3 → Ca(NO3)2 + H2O

Step 2: Balancing the equation

On the right side we have 2x N (in Ca(NO3)2 ) and 1x N on the left side (in HNO3). To balance the amount of N on both sides, we have to multiply HNO3 by 2.

Ca(OH)2 + 2HNO3 → Ca(NO3)2 + H2O

On the left side we have 4x H (2xH in Ca(OH)2 and 2x H in HNO3), on the right side we have 2x H (in H2O). To balance the amount of H on both sides, we have to multiply H2O on the right side, by 2.

Now the equationis balanced.

Ca(OH)2 + 2HNO3 = Ca(NO3)2 + 2H2O

The coefficient of Ca(OH)2 is 1

4 0

3 years ago

What is the concentration of a sodium hydroxide solution if 14.5 mL of it are exactly neutralized by 30.0 mL of a 0.500 M hydroc

rusak2 [61]

Answer:

1.03 M

Explanation:

Step 1: Write the balanced equation

NaOH + HCl ⇒ NaCl + H₂O

Step 2: Calculate the reacting moles of HCl

30.0 mL (0.0300 L) of 0.500 M HCl react.

0.0300 L × 0.500 mol/L = 0.0150 mol

Step 3: Calculate the moles of NaOH that react with 0.0150 moles of HCl

The molar ratio of NaOH to HCl is 1:1. The moles of NaOH that react are 1/1 × 0.0150 mol = 0.0150 mol.

Step 4: Calculate the molar concentration of NaOH

0.0150 moles of NaOH are in 14.5 mL (0.0145 L).

M = 0.0150 mol/0.0145 L = 1.03 M

4 0

3 years ago

What are the empirical and molecular formulas of a hydrocarbon if combustion of 2.10 g of the compound yields 6.59 g co2 and 2.7

mariarad [96]

The empirical formula of hydrocarbon is CH2

The molecular formula of the hydrocarbon is C6H12

<u><em>Explanation</em></u>

Hydrocarbon is made up of carbon and hydrogen

<h3><u><em> </em></u>Empirical formula calculation</h3>

Step 1: find the moles CO2 and H2O

moles =mass/molar mass

moles of CO2 = 6.59 g/ 44 g/mol = 0.15 moles

moles of H2O = 2.70 g / 18 g/mol = 0.15 moles

Step 2: Find the moles ratio of Co2:H2O by diving each mole by smallest mole(0.15)

that is for CO2 = 0.15/0.15 =1

For H2O = 0.15/0.15 =1

therefore the mole ratio of Co2 : H2O = 1:1 which implies that 1 mole of Co2 and 1 mole of H2O is formed during combustion reaction.

From the the law of mass conservation the number of atoms in reactant side must be equal to number of atoms in product side

therefore since there 1 atom of C in product side there must be 1 atom of C in reactant side.

In addition there is 2 H atom in product side which should be the same in reactant side.

From information above the empirical formula is therefore = CH2

Molecular formula calculation

[CH2}n= 84 g/mol

[12+ (1x2)] n = 84 g/mol

14 n = 84 g/mol

n = 6

multiply the each subscript in CH2 by 6

Therefore the molecular formula = C6H12

5 0

3 years ago