Which describes the molecule below?

How much heat (in kJ) would need to be removed to cool 150.3 g of water from 25.60°C to -10.70°C?

olga_2 [115]

Answer:

Q = -22.9 kJ

Explanation:

Given that,

Mass of water, m = 150.3 g

Water gets cool from 25.60°C to -10.70°C.

The specific heat of water, c = 4.2 J/g°C

The formula for heat needed is given by :

$Q=mc\Delta T\\\\Q=150.3\times 4.2 \times (-10.7-25.6)\\\\Q=-22914.738\\\\or\\\\Q=22.9\ kJ$

So, 22.9 kJ of heat is needed to be removed to cool.

8 0

3 years ago

What is the mass of 3.01 x 10^21 atoms of Co

OlgaM077 [116]

Answer:

0.295 g Co

General Formulas and Concepts:

Chemistry - Atomic Structure

Reading a Periodic Table
Using Dimensional Analysis
Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.

Explanation:

Step 1: Define

3.01 × 10²¹ atoms Co

Step 2: Identify Conversions

Avogadro's Number

Molar Mass of Co - 58.93 g/mol

Step 3: Convert

$3.01 \cdot 10^{21} \ atoms \ Co(\frac{1 \ mol \ Co}{6.022 \cdot 10^{23} \ atoms \ Co} )(\frac{58.93 \ g \ Co}{1 \ mol \ Co} )$ = 0.294552 g Co

Step 4: Check

We are given 3 sig figs. Follow sig fig rules and round.

0.294552 g Co ≈ 0.295 g Co

5 0

3 years ago

Solve: Turn off Show summary. Use the Choose reaction drop down menu to see other equations, and balance them. Check your answer

suter [353]

Answer: See below

Explanation:

To balance equations, you want to have the same amount of elements on the product and reactants side.

__Al+ __HCl→__AlCl₃+ __H₂

We see that there are 3 Cl on the products side and 1 on the reactants side, but there are 2 H on the product and 1 on reactant. To fulfill them both, let's put a 6 at HCl.

__Al+ 6HCl→__AlCl₃+ __H₂

Now that we have a 6 at HCl, we can fill in AlCl₃ and H₂.

__Al+ 6HCl→ 2AlCl₃+ 3H₂

All we have left is to fill in Al.

2Al+ 6HCl→ 2AlCl₃+ 3H₂

-----------------------------------------------------------------------------------------------------------------

__NaCl→ __Na+ __Cl₂

Since we have 2 Cl on the products, we must put 2 on the reactants.

2NaCl→ __Na+ 1Cl₂

With 2 NaCl, we can fill in Na.

2NaCl→ 2Na+ 1Cl₂

-----------------------------------------------------------------------------------------------------------------

__Na₂S+ __HCl→ __NaCl+ __H₂S

We see 2 Na on reactants, so we can put 2 on the products.

__Na₂S+ __HCl→ 2NaCl+ __H₂S

With 2 H and 2 Cl on the products, we can put a 2 at HCl.

1Na₂S+ 2HCl→ 2NaCl+ 1H₂S

7 0

3 years ago

What is cerium’s common molecule name?

antiseptic1488 [7]

Answer:lanthanides is the answer and here is a picture for proof

Explanation:

7 0

3 years ago

3. What effect does dark energy have on the universe?

sladkih [1.3K]

Dark energy and dark matter seem over analyzed, although they are no different than gravity and wind. Dark energy can be the pulling caused by black holes, stars, and large planets. Dark matter also is just the effect of cosmic dust and debris pushed from explosions but also pulling caused by distant gravitational bodies.

4 0

4 years ago