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Gelneren [198K]
1 year ago
8

Question 2 Classify the following statement as a prediction, observation, theory, or law. Please be sure to classify the stateme

nt exactly as it is written! A helium filled balloon floats.
Chemistry
1 answer:
vredina [299]1 year ago
5 0

Answer:

Theory

Explanation:

We are given the statement;

"A helium filled balloon floats."

Now, this statement is an attempt to explain to us why balloons float. And the reason is because they are filled with helium. This is no prediction or law or observation because to find out if the balloons contain helium, there must have been experiments to confirm that.

Thus, the statement in the question is a theory.

You might be interested in
3. The following data of decomposition reaction of thionyl chloride (SO2Cl2) were collected at a certain temperature and the con
KonstantinChe [14]

Answer:

a) First-order.

b) 0.013 min⁻¹

c) 53.3 min.

d) 0.0142M

Explanation:

Hello,

In this case, on the attached document, we can notice the corresponding plot for each possible order of reaction. Thus, we should remember that in zeroth-order we plot the concentration of the reactant (SO2Cl2 ) versus the time, in first-order the natural logarithm of the concentration of the reactant (SO2Cl2 ) versus the time and in second-order reactions the inverse of the concentration of the reactant (SO2Cl2 ) versus the time.

a) In such a way, we realize the best fit is exhibited by the first-order model which shows a straight line (R=1) which has a slope of -0.0013 and an intercept of -2.3025 (natural logarithm of 0.1 which corresponds to the initial concentration). Therefore, the reaction has a first-order kinetics.

b) Since the slope is -0.0013 (take two random values), the rate constant is 0.013 min⁻¹:

m=\frac{ln(0.0768)-ln(0.0876)}{200min-100min} =-0.0013min^{-1}

c) Half life for first-order kinetics is computed by:

t_{1/2}=\frac{ln(2)}{k}=\frac{ln(2)}{0.013min^{-1}}  =53.3min

d) Here, we compute the concentration via the integrated rate law once 1500 minutes have passed:

C=C_0exp(-kt)=0.1Mexp(-0.013min^{-1}*1500min)\\\\C=0.0142M

Best regards.

6 0
2 years ago
Zinc has a specific heat capacity of 0.390 J/goC. What is its molar heat capacity? Enter your answer numerically to three signif
ch4aika [34]

Answer:

The answer to your questions is  Cm = 25.5 J/mol°C  

Explanation:

Data

Heat capacity = 0.390 J/g°C

Molar heat capacity = ?

Process

1.- Look for the atomic number of Zinc

     Z = 65.4 g/mol

2.- Convert heat capacity to molar heat capacity

       (0.390 J/g°C)(65.4 g/mol)

- Simplify and result

   Cm = 25.5 J/mol°C  

3 0
2 years ago
The balanced reaction equation for combustion of heptane, C 7 H 16 , is C 7 H 16 + 11 O 2 ⟶ 7 CO 2 + 8 H 2 O If the reaction pro
Scorpion4ik [409]

Answer:

1) There were 7.65 grams of heptane burned

2) There reacted 38.94 grams of HCl

Explanation:

<em>1) The combustion of heptane</em>

Step 1: Data given

Mass of CO2 = 23.5 grams

Molar mass of CO2 = 44.01 g/mol

Step 2: The balanced equation:

C7H16  + 11O2 ⟶ 7CO2 + 8H2O

Step 3: Calculate moles of CO2

Moles CO2 = mass CO2 / molar mass CO2

Moles CO2 = 23.5 grams / 44.01 g/mol

Moles CO2 = 0.534 moles

Step 4: Calculate moles heptane

For 1 mole of Heptane , we need 11 moles of O2 to produce 7 moles of CO2 and 8 moles of H2O

For 0.534 moles of CO2 we have 0.534/7 = 0.0763 moles of  heptane

Step 5: Calculate mass of heptane

Mass of heptane = moles heptane * molar mass heptane

Mass heptane = 0.0763 moles * 100.21 g/mol

Mass heptane = 7.65 grams

<em></em>

<em>2) The reaction of limestone with hydrochloric acid</em>

Step 1: Data given

Mass of CO2 = 23.5 grams

Step 2: The balanced equation:

CaCO3 + 2HCl ⟶ CaCl2 + CO2 + H2O

Step 3: Calculate moles of CO2

Moles CO2 = mass CO2 / molar mass CO2

Moles CO2 = 23.5 grams / 44.01 g/mol

Moles CO2 = 0.534 moles

Step 4: Calculate moles of HCl

For 1 mol of CaCO3 we need 2 moles of HCl to produce 1 mol of CaCl2, 1 mol of CO2 and 1 mol of H2O

For 0.534 moles of CO2 we have 2*0.534 = 1.068 moles of HCl

Step 5: Calculate mass of HCl

Mass HCl = moles HCl * molar mass HCl

Mass HCl = 1.068 moles * 36.46 g/mol

Mass HCl = 38.94 grams

3 0
2 years ago
Melanie has completed the analysis of her data for the reaction of KMnO4 with malonic acid and data for a reaction of KMnO4 with
WARRIOR [948]

Answer:

See explanation

Explanation:

The relationship between the activation energy and rate of reaction is best captured by the Arrhenius equation;

k= Ae^-Ea/RT

Where;

k= rate constant

A= pre-exponential factor

Ea=activation energy

R= gas constant

T= temperature

We can see from the foregoing that, as the activation energy increases, the rate of reaction decreases and vice versa. reactions that have a very high activation energy are markedly slow.

Since the activation energy for the malonic acid reaction is found to be greater than the activation energy for the tartaric acid reaction, then the rate of the malonic acid reaction(k) will be slower than that of the tartaric acid reaction.

5 0
2 years ago
A 25-ml sample of river water was titrated with 0.0010 m k2cr2o7 and required 8.3 ml to reach the end point. what is the chemica
arsen [322]

First let us calculate the moles of K2Cr2O7 that was supplied.

moles K2Cr2O7 = 0.0010 M * 0.0083 L = 8.3x10^-6 mol

 

From the chemical formula itself, we see that there are 7 O for every mole of K2Cr2O7 or 3.5 O2. Therefore:

moles O2 = 8.3x10^-6 mol K2Cr2O7 * (3.5 mol O2 / 1 mol K2Cr2O7)

moles O2 = 2.905x10^-5 mol O2

 

Calculating for the mass of O2 in mg:

mass O2 = 2.905x10^-5 mol O2 * (32 g / mol) * (1000 mg / g)

mass O2 = 0.9296 mg

 

Therefore the chemical oxygen demand (COD) is:

COD = 0.9296 mg / (0.025 L)

<span>COD = 37.184 mg/L</span>

7 0
2 years ago
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