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3 years ago

This is the question pls help me

Chemistry

1 answer:

Kryger [21]3 years ago

4 0

Answer: B

Explanation: Graph B compares the two temperatures on separate lines so that we can see the comoparison directly, as a function of time. Not only does the graph quickly answer which condition id most favorable to colony growth, but it also hints at some behaviors that may accelerate growth as time goes on. Graph C is a possible answer, if the <u>only</u> question is which promotes growth the fastest. But the questions asks "compare," which Graph B does not allow as well as Graph C.

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How many moles are in 2.5L of 1.75 M Na2CO3

Natasha_Volkova [10]

Answer:

4.4 mol.

Explanation:

Hello!

In this case, since the formula for calculating the molarity is:

$M=n/V$

Whereas n stands for moles and V for the volume in liters; we can solve for n as shown below when we are given the volume and the molarity:

$n=V*M$

Thus, we plug in the given data to obtain:

$n=2.5L*1.75mol/L=4.4mol$

Best regards!

4 0

2 years ago

Read 2 more answers

one reaction that produces hydrogen gas can be represented by the unbalanced chemical equation Mg(s)+HCI(aq) -> MgCI(aq)+H2(g

Sonbull [250]

<h3>Answer:</h3>

128 g HCl

<h3>General Formulas and Concepts:</h3>

<u>Pre-Algebra</u>

Order of Operations: BPEMDAS

Brackets
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction

Left to Right<u> </u>

<u>Chemistry</u>

<u>Atomic Structure</u>

Reading a Periodic Table

<u>Stoichiometry</u>

Reaction Mole Ratios
Using Dimensional Analysis

<h3>Explanation:</h3>

<u>Step 1: Define</u>

[RxN - Unbalanced] Mg (s) + HCl (aq) → MgCl (aq) + H₂ (g)

↓

[RxN - Balanced] 2Mg (s) + 2HCl (aq) → 2MgCl (aq) + H₂ (g)

[Given] 3.25 mol Mg

[Solve] x g HCl

<u>Step 2: Identify Conversions</u>

[RxN] 2 mol Mg → 2 mol HCl

[PT] Molar Mass of H - 1.01 g/mol

[PT] Molar Mass of Cl - 35.45 g/mol

Molar Mass of HCl - 1.01 + 35.45 = 36.46 g/mol

<u>Step 3: Stoich</u>

[S - DA] Set up: $\displaystyle 3.25 \ mol \ Mg(\frac{2 \ mol \ HCl}{2 \ mol \ Mg})(\frac{36.46 \ g \ HCl}{1 \ mol \ HCl})$
[S - DA] Multiply/Divide [Cancel out units]: $\displaystyle 127.61 \ g \ HCl$

<u>Step 4: Check</u>

<em>Follow sig fig rules and round. We are given 3 sig figs.</em>

127.61 g HCl ≈ 128 g HCl

3 0

2 years ago

How many moles is 22.4 liters of oxygen gas at standard temperature and pressure represent

makkiz [27]

Answer:

So 1 mole

Explanation:

PV = nRT

P = Pressure atm

V = Volume L

n = Moles

R = 0.08206 L·atm·mol−1·K−1.

T = Temperature K

standard temperature = 273K

standard pressure = 1 atm

22.4 liters of oxygen

Ok so we have

V = 22.4

P = 1 atm

PV = nRT

n = PV/RT

n = 22.4/(0.08206 x 273)

n = 22.4/22.40

n = 1 mole

7 0

3 years ago

Please i need help really quickly on this. thank you

prohojiy [21]

Answer:

the error could have been the fact that the unit for volume wasn't changed from cm³ to dm³

hence the calculation error

the solution to this would be first dividing the volume by 1000 to get that same amount in dm³ which is the standard unit to be used for volume-density calculations

6 0

3 years ago

1. A gas expands and does p-v work on the surroundings equal to

azamat

The change in energy of the system : -63 J

<h3>Further explanation</h3>

Given

279 J work

216 J heat

Required

The change in energy

Solution

Laws of thermodynamics 1

ΔU=Q+W

Rules :

receives heat, Q +
releases heat, Q -
work is done by a system, W -
work is done on a system, W +

a gas work on the surrounding : W =-279 J

a gas absorb heat from surrounding : Q = +216 J

Internal energy :

= -279+216

= -63 J

3 0

2 years ago