All categories

3 years ago

Which statement is true about endothermic and exothermic reactions

Chemistry

1 answer:

AfilCa [17]3 years ago

4 0

Answer:

The products have less potential energy than the reactants in an exothermic reaction.

Explanation:

took the test

You might be interested in

HELP!!!!!!!!!!!! ASAP!!!!!!!!!!!!!!!!!!! CHEMISTRY TEST!!!!!!!!!!!!!! 53 POINTS

lbvjy [14]

Answer:

9.1 KJ

Explanation:

First we must find the number of moles of HBr involved;

number of moles of HBr= mass of HBr/ molar mass of HBr

But molar mass of HBr= 80.91 g/mol

Given mass of HBr from the question= 20.1g

Hence;

Number of moles of HBr= 20.1 g/80.91g

Number of moles of HBr= 0.25 moles of HBr

If 2 moles of HBr has a heat of formation of 72.80KJ

Then 0.25 moles of HBr will have a heat of formation of 0.25× 72.80/2= 9.1 KJ

Therefore; 20.1 g of HBr will have a heat of formation of 9.1 KJ

3 0

3 years ago

Vinegar is an aqueous solution of acetic acid, ch3cooh. a 5.00 ml sample of a particular vinegar requires 26.90 ml of 0.175 m na

Fed [463]

The molarity of acetic acid in the vinegar is 0.94 M

calculation

Step 1: write the balanced equation between CH3COOH + NaOH

that is CH3COOH + NaOH → CH3COONa + H2O

step 2 : find the moles of NaOH

moles =molarity x volume in L

volume in liters = 26.90/1000=0.0269 l

moles = 0.175 mol /L x 0.0269 L =0.0047 moles of NaOH

Step 3: use the mole ratio to find moles of CH3COOH

that is the mole ratio of CH3COOH: NaOH is 1:1 therefore the moles of CH3COOH is =0.0047 moles

Step 4: find the molarity of CH3COOH

molarity = moles/volume in liters

volume in liter = 5.00/1000 =0.005 l

molarity is therefore=0.0047 moles/ 0.005 l = 0.94 M

4 0

4 years ago

Put all chemicals down the drain. True or false?

Dovator [93]

False, many chemicals can be toxic to the drainage systems, and can make their way into the ocean harming sea life.

4 0

3 years ago

Read 2 more answers

An ordered list of chemical substances is shown.

Alex73 [517]

answer : the correct option is, (B) 2, 3 and 6.

3 0

3 years ago

A mysterious compoud with the chemical formula MX (Ksp 1.27x10-36) is present in two different solutions. What is its molar solu

qwelly [4]

Answer: The molar solubility of MX is $2.54\times 10^{-36}M$

Explanation:

We are given:

$K_{sp}(MX)=1.27\times 10^{-36}$

The chemical equation for the ionization of MX follows:

$MX\rightleftharpoons M^+(aq.)+X^-(aq.)$

S S

The expression of $K_{sp}$ for above equation is:

$K_{sp}=S\times S$ ......(1)

The chemical equation for the ionization of $M_2SO_4$ follows:

$M_2SO_4\rightleftharpoons 2M^+(aq.)+SO_4^{2-}(aq.)$

0.25M 0.5M 0.25M

Total concentration of cation from both the equation is:

$[M^+]=0.5+S$

As, $K_{sp}(MX)$ , so S is also very very less than 1 and can be easily neglected.

So, $[M^+]=0.5M$

Putting values in equation 1, we get:

$1.27\times 10^{-36}=0.5\times S\\\\S=2.54\times 10^{-36}M$

Hence, the molar solubility of MX is $2.54\times 10^{-36}M$

4 0

3 years ago