1. What type of reaction occurs when an acid reacts with a base?

Some students decide to plant their own garden. They want to eat a more plant-based diet For meat, they will buy locally from a

ozzi

Answer:

composting scraps

recycling is the action or process of converting waste into reusable material.

7 0

3 years ago

A first-order reaction has a half-life of 29.8 s . How long does it take for the concentration of the reactant in the reaction t

lutik1710 [3]

Answer : The time taken for the concentration of the reactant in the reaction to fall to one-fourth of its initial value is, 12.4 seconds.

Explanation :

Half-life = 29.8 s

First we have to calculate the rate constant, we use the formula :

$k=\frac{0.693}{t_{1/2}}$

$k=\frac{0.693}{29.8s}$

$k=0.0232s^{-1}$

Now we have to calculate the time passed.

Expression for rate law for first order kinetics is given by:

$t=\frac{2.303}{k}\log\frac{a}{a-x}$

where,

k = rate constant = $0.0232s^{-1}$

t = time passed by the sample = ?

a = let initial amount of the reactant = x M

a - x = amount left after decay process = $x-\frac{1}{4}\times (x)=\frac{3}{4}\times (X)=\frac{3x}{4}M$

Now put all the given values in above equation, we get

$t=\frac{2.303}{0.0232s^{-1}}\log\frac{x}{(\frac{3x}{4})}$

$t=12.4s$

Therefore, the time taken for the concentration of the reactant in the reaction to fall to one-fourth of its initial value is, 12.4 seconds.

7 0

4 years ago

In the explosion of a hydrogen-filled balloon, 0.80 g of hydrogen reacted with 6.4 g of oxygen. How many grams of water vapor ar

mylen [45]

0.4 moles H2O x (18.0 g / mole) = 7.2 g H2O

Explanation:

write the values given in the question

In an explosion of hydrogen balloon, 0.80g of hydrogen is reacted with 6.4g of oxygen.

Write the balanced equation

2 H2 + O2 ---> 2 H2O

0.80 g H2 x (1 mole / 2g) = 0.4 moles H2

6.4 g O2 x (1 mole / 32g) = 0.2 moles O2

from balanced equation, 2 moles H2 react with 1 mole O2

therefore

0.4 moles H2 x (1 mole O2 / 2 moles H2) = 0.2 moles O2

since we need 0.2 moles O2 to react with all the H2 and we have exactly that amount, the amounts are said to be

"stoichiometric" and either reactant can be considered limiting

from the balanced equation, 2 moles H2 --> 2 moles H2O.. therefore

0.4 moles H2 x (2 moles H2O / 2 moles H2) = 0.4 moles H2O

Then

0.4 moles H2O x (18.0 g / mole) = 7.2 g H2O

8 0

3 years ago

The molar mass of argon is 40g / mol what is the molar mass of a gas if it effuses at 0.91 times the speed of argon gas

Effectus [21]

To determine the molar mass of the unknown gas, we use Graham's Law of Effusion where it relates the effusion rates of two gases with their molar masses. It is expressed as r1/r2 = √M2/M1. We calculate as follows:

Let 1 = argon gas
2 = unknown gas

r2 = 0.91r1
r1/r2 = 1/0.91

1/0.91 = √M2/M1 = √M2/40
M2 = 48.30 g/mol

8 0

4 years ago

What is a system called when neither energy nor matter is exchanged between the system and the surroundings?

Evgesh-ka [11]

Answer:

Isolated system

Explanation:

If we are talking about theremodynamic system answer is ISOLATED SYSTEM

If we talking about mechanic annswer is CLOSED SYSTEM

CLOSED SYSTEM IN CLASSICAL MECHANICS = ISOLATED SYSTEM IN THERMODYNAMICS.

4 0

4 years ago