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3 years ago

What is a sign that a chemical change has occurred?

Chemistry

2 answers:

blondinia [14]3 years ago

3 0

Answer:

The production of heat, light, or smoke is observed.

vladimir1956 [14]3 years ago

3 0

The production of heat, light or smoke is observed and the state of matter has changed

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Determine the net force acting on the object. Then, write whether or not there will be a change in motion. If yes, write the dir

quester [9]

Answer:

Net force= -5N+5N =0

Therefore there is no change in motion

Explanation:

3 0

3 years ago

The empirical formula of a compound is NO2. Its molecular mass is 9.2g/mol. What is its molecular formula?

Natali5045456 [20]

Answer:

Molecular formula = N2O4

Explanation:

The empirical formula of a compound is NO2. Its molecular mass is 92g/mol. What is its molecular formula?

Step 1: Data given

The empirical formula = NO2

The molecular formula = NO2

Molar mass N = 14 g/mol

Molar mass O = 16 g/mol

Step 2: Calculate molecular mass of the empirical formula

Molar mass NO2 = molar mass N + Molar mass of 2*O

Molar mass NO2 = 14 + 2*16

Molar mass = 46 g/mol

Step 3: Calculate the molecular formula

We have to multiply the empirical formula by n

n = molecular mass / molecular mass of the empirical formula

n = 92 g/mol / 46 g/mol

n = 2

We have to multiply the empirical formula by 2

Molecular formula = 2*(NO2)

Molecular formula = N2O4

3 0

4 years ago

HELPPPPP ASAP PLSSSS !!!!!!!!!

mylen [45]

Answer:

maybe i can help for you where the question

6 0

2 years ago

As bond number increases (double bonds rather than single, triple rather than double etc. ), bond length and bond energy.

Likurg_2 [28]

As bond number increases (double bonds rather than single, triple rather than double etc. ), bond length decreases and bond energy increases

Reason-Charges that are spaced apart are described by a dipole moment. There are two critical criteria that must be taken into account when assessing if a molecule has a dipole moment. It must first possess polar covalent bonds. The individual dipoles must not cancel out in the molecular structure, which is the second requirement. Because Br2 is not a polar molecule, it lacks a polar covalent bond.A bond number is a simple addition of two numbers that total the sum. Using number bonds, one can quickly determine the answer without performing any calculations. We can see from the example that when we see a number bond, we know the answer without having to calculate.

Learn more about bond number here:

brainly.com/question/10429880

#SPJ4

4 0

2 years ago

Suppose 11.4g of ammonium chloride is dissolved in 250 ml of a 0.3M aqueous solution of potassium carbonate. Calculate the final

Sindrei [870]

Answer:

The molarity of the final ammonium cation is 0.252M

Explanation:

Step 1: Data given

Mass of ammonium chloride (NH4Cl) = 11.4 grams

Volume of 0.3 M aqueous solution of potassium carbonate (K2CO3) = 250 mL = 0.250L

Step 2: The balanced equation

2NH4Cl + K2CO3 → 2KCl + (NH4)2CO3

Step 3: Calculate moles of (NH4)Cl

moles (NH4)Cl = 11.4 grams /53.49 g/mol

Moles (NH4)Cl = 0.213 moles

Step 4: Calculate moles of K2CO3

Moles K2CO3 = Molarity * Volume

Moles K2CO3 = 0.3M * 0.250 L = 0.075 moles

Step 5: Calculate moles (NH4)Cl at the equilibrium

For 2 moles (NH4)Cl consumed, we need 1 mole of K2CO3 to produce 2 KCl and 1 mole of (NH4)2CO3

(NH4)2CO3l will dissolve in 2NH4+ + CO32-

Moles (NH4)2Cl = 0.213 moles - 2*0.075 = 0.063 moles

Moles NH4+ = moles (NH4)Cl = 0.063 moles

Step 6: Calculate Molarity of NH4+

Molarity = Moles / volume

Molarity of NH4+ = 0.063 moles / 0.250 L

Molarity of NH4+ = 0.252 M

The molarity of the final ammonium cation is 0.252M

5 0

3 years ago