Which pair of elements are the most similar? A. Ca and F B. Na and Cl C. Ne and Ar D. K and Ca

1. Given below are the figures showing particles of a matter in its three

stepan [7]

Answer:the answer is c

Explanation:

6 0

3 years ago

How many moles of sodium cyanide (NaCN) would be needed to produce 4.2 moles of sodium sulfate (Na2SO4)? H2SO4 + 2NaCN → 2HCN +

leonid [27]

The purpose of a chemical equation is to relate the amounts of reactants to the amounts of products based on the rate each is consumed. In this problem, one mole of sulfuric acid is consumed along with two moles of sodium cyanide to produce two moles of hydrocyanic acid and one mole of sodium sulfate. The relationship between sodium cyanide and sodium sulfate is 2:1, meaning that two moles of NaCN is required to produce one mole of sodium sulfate.

To produce 4.2 moles of sodium sulfate, two times this amount of NaCN is required. This means that you would need 8.4 moles of sodium cyanide.

Hope this helps!

4 0

3 years ago

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A shiny chunk of metal is found to have a mass of 37.28g. The metal is dropped into a graduated cylinder which contains 20.0 mL

Amanda [17]

Answer: The density of the material is 2.66 g/mL and it is likely this is made of Aluminum

Explanation:

The first step to know the material of the chunk of metal is to calculate its density. The general formula for density is P (density) = $\frac{m (mass)}{ v (volume)}$ . Moreover, in this case, it is known the mass is 37.28 g, but the volume is not directly provided. However, we know the water in the graduated cylinder had a volume of 20.0 mL and this increased to 34.0 mL when the chunk of metal is added, this means the volume of the metal is 14 mL (34.0 mL - 20.0 mL = 14 mL). Now let's calculate the density:

$P =$ $\frac{37.28g}{14.0mL}$

$P = 2.66 g/mL$

This means the density of this metal is 2.66 g/mL, which can be rounded as 2. 7 g/mL, and according to the chart, this is the density of aluminum. Therefore, this material of this chunk is aluminum.

6 0

4 years ago

Given the following unbalanced equation:

antiseptic1488 [7]

<h3>Answer:</h3>

11.84 mol CoF₂

<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>

Moles

<u>Stoichiometry</u>

Using Dimensional Analysis
Analyzing Reactions RxN

<h3>Explanation:</h3>

<u>Step 1: Define</u>

[RxN - Unbalanced] CoCl₂ + F₂ → CoF₂ + Cl₂

[RxN - Balanced] CoCl₂ + F₂ → CoF₂ + Cl₂

[Given] 11.84 moles CoCl₂

[Solve] moles CoF₂

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

[RxN] 1 mol CoCl₂ → 1 mol CoF₂

<u>Step 3: Stoich</u>

[DA] Set up: $\displaystyle 11.84 \ mol \ CoCl_2(\frac{1 \ mol \ CoF_2}{1 \ mol \ CoCl_2})$
[DA] Multiply/Divide [Cancel out units]: $\displaystyle 11.84 \ mol \ CoF_2$

7 0

3 years ago

The reaction between A2 (two large red spheres) and B2 (two small blue spheres) to produce AB is shown in the diagram. The react

drek231 [11]

Answer:

B₂

Explanation:

The limiting reactant is always a reactant. You can determine which reactant is limiting by identifying which has the smaller mole-to-mole ratio with the product. This ratio can be found via the coefficients of the balanced reaction.

4 A₂ + 3 B₂ ---> 6 AB

4 moles A₂
------------------ = mole-to-mole ratio A₂/AB
6 moles AB

3 moles B₂
------------------ = mole-to-mole ratio B₂/AB
6 moles AB

Since the mole-to-mole ratio between B₂ and AB is smaller, B₂ must be the limiting reactant.

3 0

2 years ago