Ask question

Ask question

All categories

4 years ago

9

After observing and asking questions, what is the next step in the scientific method? A. analyzing data B. drawing conclusions C

. gathering information (doing research) D. testing the hypothesis

1 answer:

Artemon [7]4 years ago

8 0

You really want to make a hypothesis first, and THEN test the hypothesis so the answer would be D).

You might be interested in

Correct the name to match the formula of the following compounds: (a) calcium(ll) dichloride. CaClZ; (b) copper(|l) oxide. Cu20;

tangare [24]

Answer:

Explanation:

Incorrect name correct name

a) calcium dichloride calcium chloride

b) copper(II) oxide copper(I) oxide

c) stannous tetrafluoride stannic fluoride

d) hydrogen chloride acid hydrochloric acid

5 0

3 years ago

Consider the reaction Mg₂Si(s) + 4 H₂O(ℓ) → 2 Mg(OH)₂(aq) + SiH₄(g). How many grams of silane gas (SiH₄) are formed if 25.0 g of

Neko [114]

Answer:

10.60 grams of silane gas are formed.

Explanation:

From the reaction:

Mg₂Si(s) + 4H₂O(l) → 2Mg(OH)₂(aq) + SiH₄(g)

We know that the limiting reactant is Mg₂Si, so to find the mass of SiH₄ formed we need to calculate the number of moles of Mg₂Si:

$\eta_{Mg_{2}Si} = \frac{m_{Mg_{2}Si}}{M_{Mg_{2}Si}}$

Where:

m: is the mass of Mg₂Si = 25.0 g

M: is the molar mass of Mg₂Si = 76.69 g/mol

$\eta_{Mg_{2}Si} = \frac{m_{Mg_{2}Si}}{M_{Mg_{2}Si}} = \frac{25.0 g}{76.69 g/mol} = 0.33 moles$

Now, the stoichiometric relation between Mg₂Si and SiH₄ is 1:1 so:

$\eta_{Mg_{2}Si} = \eta_{SiH_{4}} = 0.33 moles$

Finally, the mass of SiH₄ is:

$m_{SiH_{4}} = \eta_{SiH_{4}}*M_{SiH_{4}} = 0.33 moles*32.12 g/mol = 10.60 g$

Therefore, 10.60 grams of silane gas are formed.

I hope it helps you!

3 0

3 years ago

A 4.10 −g sample of a mixture of CaO and BaO is placed in a 1.00-L vessel containing CO2 gas at a pressure of 735 torr and a tem

insens350 [35]

Answer:

The mass % of CaO is 9.37%%

Explanation:

<u>Step 1: </u>Data given

Mass of the mixture = 4.10 grams

Volume of the vessel = 1.00 L

The vessel contains CO2 with a pressure of 735 torr and temperature = 26 °C

The pressure of the remaining CO2 is 155 torr

<u>Step 2:</u> The balanced equation

CaO/BaO + CO2 → CaCO3 /BaCO3

.

<u>Step 3</u>: Calculate moles CO2 (via ideal gas law)

CO2 is the only gas, this means the drop in the pressure is caused by CO2

Δp = 735 torr - 155 torr = 580 torr

580 torr = 0.763 atm

n = PV/RT = (0.763atm)(1.00L) / (0.08206 L*atm/K*mol)(299) = 0.0391 moles CO2 initial

moles reacted = 0.0311 moles CO2

Step 4: Calculate mass of CaO and BaO

Let's suppose x = mass of CaO. Then mass of BaO = 4.10-x.

In the balanced equation, we notice the mole ratio of CaO/BaO with CO2 is 1:1. This means the number of moles CaO + moles BaO = Number of moles CO2

moles CaO + moles BaO = moles CO2

x/56.08 + (4.10-x)/153.33 = 0.0311

56.08 (x/56.08 + (4.10-x)/153.33) = (56.08)(0.0311)

x + (0.366)(4.10-x) = 1.744

x + 1.5006 - 0.366x = 1.744

0.634x = 0.2434

x = 0.384g CaO

4.1-x = g BaO = 3.716 grams

%CaO = (0.384 g / 4.10 g) x 100 = 9.366% ≈ 9.37

The mass % of CaO is 9.37%

7 0

4 years ago

Which of the following represents a physical change in matter

Alik [6]

There's nothing following?

5 0

3 years ago

Write a qualitative example ?<br> urgent response plssss

ArbitrLikvidat [17]

Explanation:profeción: arquitecto ,m edi co ingeniero,abogado

6 0

4 years ago