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2 years ago

HELP ASAP! I will give brainiest if you answer all questions correctly.

Chemistry

2 answers:

oksano4ka [1.4K]2 years ago

4 0

Answer:

28) -88kj

29) 300kj

30) -204kj

DaniilM [7]2 years ago

4 0

Answer:

28). 261

29). 788

30).-6201

Explanation:

I just took lesson and it said those were correct, I added screenshots of the lesson if you need it :)

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Now explain your diagnosis. Start your argument by writing something like this: "My group believes that Elisa has/does not have

likoan [24]

Answer:

Explanation:I would need more info to understand this question but explaining molecules is pretty easy tho

4 0

1 year ago

Suppose you perform a calorimeter experiment to determine the molar heat of neutralization of an unknown acid, H A HA, with sodi

Black_prince [1.1K]

Answer:

-86.02 kJ/ mole

Explanation:

The moles of the acid used = Molarity × Volume (L) =

= 0.50 (0.0372 L)

= 0.0186 moles

The heat released = -1.6 kJ

∴ 0.0186 moles neutralization of HA heat is: -1.6 kJ

The molar heat of neutralization due to one mole of the unknown acid = -1.6/0.0186

= -86.02 kJ/ mole

5 0

2 years ago

A chemist has 2.0 mol of methanol (CH3OH). The molar mass of methanol is 32.0 g/mol. What is the mass, in grams, of the sample?

rodikova [14]

Answer:

$\boxed {\boxed {\sf D. \ 64 \ grams }}$

Explanation:

Given the moles, we are asked to find the mass of a sample.

We know that the molar mass of methanol is 32.0 grams per mole. We can use this number as a fraction or ratio.

$\frac{32 \ g \ CH_3OH}{1 \ mol \ CH_3OH}$

Multiply by the given number of moles, which is 2.0

$2.0 \ mol \ CH_3OH *\frac{32 \ g \ CH_3OH}{1 \ mol \ CH_3OH}$

The moles of methanol will cancel each other out.

$2.0 \ *\frac{32 \ g \ CH_3OH}{1 }$

The denominator of 1 can be ignored.

$2.0 * 32 \ g\ CH_3OH$

Multiply.

$64 \ g \ CH_3OH$

There are 64 grams of methanol in the sample.

3 0

2 years ago

A wave hits a wall as shown. A brick wall with a green arrow pointing to the wall from below and right at a shallow angle. Anoth

Dominik [7]

Answer:

A wave reflection interaction (reflected by the wall)

Explanation:

In a reflection, the propagating wave is bounced off the reflecting surface because the medium of the surface prevents the propagation of the wave through it, such that wave is redirected at an angle equal to the angle of incident on the reflecting surface

Reflection takes place with the different forms of waves, such as sound wave, water waves, and light wave

The objects around us are seen with the aid of reflection of light from a light source such that the reflected light enters our eyes after being reflected on the surface of the object, and the object is seen.

3 0

2 years ago

Read 2 more answers

Determine the total number of moles of ions in 40.0 ml of a 0.345 m solution of the strong electrolyte mgcl2

Sedbober [7]

A strong electrolyte like MgCl2 dissociates completely as per the following reaction:

$MgCl_2 ----\ \textgreater \ Mg^{2+} + 2Cl^-$

As you can see, from 1 molecule of MgCl2 produces 3 ions on dissociation.
So, 1 mole of MgCl2 produces 3 moles of ions.

Now, Moles of MgCl2 = Volume x Molarity

= 0.04 x 0.345 [Change volume to Litres]
= 0.0138 moles

Now, total moles of ions = 0.0138 x 3 = 0.0414

6 0

2 years ago