Whats principle of Aristotle's do scientist use today

aluminum has a specific heat of 0.897 j/g°C. how much heat is needed to raise the temperature of a 79 gram piece of aluminum 28°

frutty [35]

Answer:

Approximately 2000 J.

General Formulas and Concepts:

Thermodynamics

Specific Heat Formula: q = mcΔT

q is heat (in J)
m is mass (in g)
c is specific heat (in J/g °C)
ΔT is change in temperature (in °C or K)

Explanation:

Step 1: Define

Identify variables

[Given] c = 0.897 J/g °C

[Given] m = 79 g

[Given] ΔT = 28°C

[Solve] q

Step 2: Solve for q

Substitute in variables [Specific Heat Formula]: q = (79 g)(0.897 J/g °C)(28 °C)
Multiply [Cancel out units]: q = (70.863 J/°C)(28 °C)
Multiply [Cancel out units]: q = 1984.16 J

Step 3: Check

Follow sig fig rules and round. We are given 2 sig figs as our lowest.

1984.16 J ≈ 2000 J

6 0

3 years ago

The chemical equation for a reaction between K2Cr2O7 and HCl is shown. K2Cr2O7 + 14HCl → 2CrCl3 + 2KCl + 3Cl2 + 7H2O

guapka [62]

Answer: The correct answer is Option b.

Explanation:

Oxidizing agent is defined as the chemical reagent which helps the other chemical compound to get oxidized and itself gets reduced. The oxidation state for these species gets reduced because they are undergoing reduction reaction.

For the given chemical equation:

$K_2Cr_2O_7+14HCl\rightarrow 2CrCl_3+2KCl+3Cl_2+7H_2O$

Oxidation state of Chromium is getting reduced from +6 to +3 and oxidation state of chlorine getting increased from -1 to 0.

Hence, $K_2Cr_2O_7$ acts like and oxidizing agent because it is itself getting reduced to $CrCl_3$

Therefore, the correct answer is Option b.

4 0

3 years ago

Using the Rydberg formula, calculate the initial energy level when an electron in a hydrogen atom transitions into n= 2 and emit

EleoNora [17]

Answer:

1

Explanation:

Using the Rydberg formula as:

$\frac {1}{\lambda}=R_H\times Z^2\times (\frac {1}{n_{1}^2}-\frac {1}{n_{2}^2})$

where,

λ is wavelength of photon

R = Rydberg's constant (1.097 × 10⁷ m⁻¹)

Z = atomic number of atom

n₁ is the initial final level and n₂ is the final energy level

For Hydrogen atom, Z= 1

n₂ = 2

Wavelength = 410.1 nm

Also,

1 nm = 10⁻⁹ m

So,

Wavelength = 410.1 × 10⁻⁹ m

Applying in the formula as:

$\frac {1}{410.1\times 10^{-9}}=1.097\times 10^7\times 1^2\times (\frac {1}{n_{1}^2}-\frac {1}{2^2})$

Solving for n₁ , we get

n₁ ≅ 1

3 0

3 years ago

Read 2 more answers

why are plasmas of great interest to scientists or manufacturers. descride 2 current uses of plasmas and describe 1 way scientis

Helga [31]

Answer:

Plasmas of great interest to scientists or manufacturers as

Plasma is electrically charged gases that contain considerable charged particles that can change the behavior of the substance.

Current uses of plasmas:

First, it is used to make semiconductors for different types of electronic equipment

Secondly, they're used in making transmitters for high-temperature films.

Way scientists and engineers hope to use plasmas in the future:

The scientists are hoping to use plasma in the future to get rid of all hazardous wastes through a process called plasma gasification.

6 0

3 years ago

How many molecules of ammonia are formed in the following equation: N2+3H2→2NH3

Katena32 [7]

Answer:

two molecules of ammonia are formed by the reaction of one nitrogen and three hydrogen molecules.

Explanation:

The balanced chemical equation provides information on:

Reactants: those are the compounds that appear of the left side of the equation, each with its chemical formula.

Products: those are the compounds that appear on the right side of the equation, again, each with its chemical formula.

Ratio: the coefficients of each compound (the number to the left of the chemical formula) represent the ratio of the number of molecules that react and are formed.

In the given equation you have:

Equation: N₂ + 3H₂ → 2NH₃

The coefficients are 1 for nitrogen, 3 for hydrogen, and 2 for ammonia. Hence, 2 molecules of ammonia are formed by the reaction of 1 molecule of nitrogen and 3 molecules of hydrogen.

7 0

3 years ago