What does a control group show in an experimental investigation?

3. What is the mass of an object with a volume of 4 L and a density of 1.25 g/mL?

ch4aika [34]

Answer:

5000g

Explanation:

mass= density × volume

Since the unit of density here is g/mL, we need to convert the volume to mL.

1L= 1000mL

4L= 4 ×1000 = 4000 mL

Mass of object

= 1.25 ×4000

= 5000g

3 0

3 years ago

Read 2 more answers

A force of 5000 newtons is applied to a 1200 kg car at rest. What is its acceleration?

insens350 [35]

The formula for acceleration if rearranged based on the force equation is- force over mass. So 5000/1200=4.16

Your answer is 4 m/s squared.

4 0

3 years ago

811.68 J of energy are used on a 95g chunk of unknown metal. Calculate the resulting temperature change if the specific heat of

Ivan

Answer:

16 °C

Explanation:

Step 1: Given data

Provided heat (Q): 811.68 J

Mass of the metal (m): 95 g

Specific heat capacity of the metal (c): 0.534 J/g.°C

Step 2: Calculate the temperature change (ΔT) experienced by the metal

We will use the following expression.

Q = c × m × ΔT

ΔT = Q/c × m

ΔT = 811.68 J/(0.534 J/g.°C) × 95 g = 16 °C

6 0

3 years ago

Reaction rate is expressed in terms of changes in the concentration of reactants and products. Write a balanced equation for the

KengaRu [80]

Answer : The balanced equations will be:

$CH_4+2O_2\rightarrow 2H_2O+CO_2$

Explanation :

The general rate of reaction is,

$aA+bB\rightarrow cC+dD$

Rate of reaction : It is defined as the change in the concentration of any one of the reactants or products per unit time.

The expression for rate of reaction will be :

$\text{Rate of disappearance of A}=-\frac{1}{a}\frac{d[A]}{dt}$

$\text{Rate of disappearance of B}=-\frac{1}{b}\frac{d[B]}{dt}$

$\text{Rate of formation of C}=+\frac{1}{c}\frac{d[C]}{dt}$

$\text{Rate of formation of D}=+\frac{1}{d}\frac{d[D]}{dt}$

$Rate=-\frac{1}{a}\frac{d[A]}{dt}=-\frac{1}{b}\frac{d[B]}{dt}=+\frac{1}{c}\frac{d[C]}{dt}=+\frac{1}{d}\frac{d[D]}{dt}$

From this we conclude that,

In the rate of reaction, A and B are the reactants and C and D are the products.

a, b, c and d are the stoichiometric coefficient of A, B, C and D respectively.

The negative sign along with the reactant terms is used simply to show that the concentration of the reactant is decreasing and positive sign along with the product terms is used simply to show that the concentration of the product is increasing.

Now we have to determine the balanced equations corresponding to the following rate expressions.

$Rate=-\frac{d[CH_4]}{dt}=-\frac{1}{2}\frac{d[O_2]}{dt}=+\frac{1}{2}\frac{d[H_2O]}{dt}=+\frac{d[CO_2]}{dt}$

The balanced equations will be:

$CH_4+2O_2\rightarrow 2H_2O+CO_2$

5 0

3 years ago

A sample of a pure element has a mass of 45.6g and contains 4.19 x 10 23 atoms. Identify the element.

max2010maxim [7]

<h2>Answer:</h2>

ZINC

<h2>Explanation:</h2>

<em>To identify the element based on the informartion given, we have to find the molar mass since this mass is unique to each element.</em>

Molar mass = mass ÷ moles

<em>We already know the mass based on the question, as such we now need to find the # of moles.</em>

Since 1 mole contains 6.02214 × 10²³ atoms

then let x moles contain 4.19 × 10²³ atoms <em>(given in the question)</em>

<em> </em><em> </em> ⇒ x = (4.19 × 10²³ atoms × 1 mol) ÷ 6.02214 × 10²³ atoms

x = 0.69577 mol

<em>Now that we have the moles we can substitute it into the molar mass equation and solve for the molar mass.</em>

⇒ molar mass = 45.6 g ÷ 0.69577 mol

⇒ molar mass ≈ 65.54 g/mol

This molar mass is closest to that of ZINC.

7 0

3 years ago