How much heat energy in joules is needed to raise the temperature of 500.0 g of water from 10.0°C to 63.5°C

Which two letters has the most kinetic energy? W X Y Z

hichkok12 [17]

Answer:

x and y

Explanation:

3 0

2 years ago

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Which of the following combustion reactions is balanced correctly? A. C4H6 + 5.5O2 4CO2 + 3H2O B. C4H6 + 4O2 4CO2 + 3H2O C. C4H6

Airida [17]

You must verify that the number of atoms of each type is equal on both sides of the chemical equation: same number of C, same number of H and same number of O on both sides.

A. C4H6 + 5.5O2 ---> 4CO2 + 3H2O

element reactant side product side

C 4 4
H 6 3*2 = 6
O 5.5 * 2 = 11 4*2 + 3 = 11

Then, this equation is balanced.

Do the same with the other equations if you want to verify that they are not balanced.

Answer: option A.

5 0

3 years ago

How many grams of sodium ions are in na2so4?

LiRa [457]

Answer:

142.04

Explanation:

4 0

3 years ago

At 20.°C, a 1.2-gram sample of Mg ribbon reacts rapidly with 10.0 milliliters of 1.0 M HCl(aq). Which change in conditions would

Pavlova-9 [17]

Answer: (2) decreasing the concentration of HCl(aq) to 0.1 M

Explanation: Rate of a reaction depends on following factors:

1. Size of the solute particles: If the reactant molecules are present in smaller size, surface of particles and decreasing the size increases the surface area of the solute particles. Hence, increasing the rate of a reaction.

2. Reactant concentration: The rate of the reaction is directly proportional to the concentration of reactants.

3. Temperature: Increasing the temperature increases the energy of the molecules and thus more molecules can react to give products and rate increases.

(1) Increasing the initial temperature to 25°C will increase the reaction rate.

(2) Decreasing the concentration of HCl(aq) to 0.1 M will decrease the reaction rate due to lesser concentration.

(3) Using 1.2 g of powdered Mg will increase the reaction rate due to large surface area.

(4) Using 2.4 g of Mg ribbon will increase the reaction rate due to high concentration of reactants.

7 0

3 years ago

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A buffer contains 0.18 mol of propionic acid (C2H5COOH) and 0.26 mol of sodium propionate (C2H5COONa) in 1.20 L. What is the pH

Yuki888 [10]

Answer:

1) pH = 5.05

2) pH = 5.13

3) pH = 4.97

Explanation:

Step 1: Data given

Number of moles of propionic acid = 0.18 moles

Number of moles sodium propionate = 0.26 moles

Volume = 1.20 L

Ka = 1.3 * 10^-5 → pKa = 4.989

Step 2: Calculate concentrations

Concentration = moles / volume

[acid]= 0.18/ 1.2 =0.150 M

[salt]= 0.26/ 1.3 = 0.217 M

pH = 4.89 + log(0.217/0.150)=5.05

What is the pH of the buffer after the addition of 0.02 mol of NaOH?

moles acid = 0.18 - 0.02 = 0.16

[acid]= 0.16/ 1.2=0.133 M

moles salt = 0.26 + 0.02 = 0.28

[salt]= 0.28/ 12=0.233

pH = 4.89 + log 0.233/ 0.133 = 5.13

What is the pH of the buffer after the addition of 0.02 mol of HI?

moles acid = 0.18+ 0.02 = 0.20 moles

[acid]= 0.20/ 1.2 = 0.167 M

[salt]= 0.26 - 0.02= 0.24 moles

[salt]= 0.24/ 1.2 = 0.20 M

pH = 4.89 + log 0.20/ 0.167= 4.97

8 0

2 years ago