alkaline
C2Pronunciation
UK
- /ˈælkəlˌaɪn/
US
- /ˈælkəˌlaɪn/
Description
- basic (pH > 7)
- opposite of acidic
- neutralizes acids
- often soapy/slippery
Imagine lemons—they're sour, right? That's because they're acidic. Now picture baking soda—it doesn't have that sharp bite. Baking soda is alkaline, meaning it’s basic—the opposite of acidic. The word "alkaline" describes substances that are basic (with a pH above 7 in water) and that can neutralize acids; they often feel slippery or soapy to the touch.
You'll hear about alkalinity in chemistry, but also in everyday life: alkaline batteries are a common type of household battery, and gardeners talk about alkaline soil when they test soil pH. You may also hear about “alkaline” eating or drinking, though the body keeps blood pH tightly regulated. Think of it as a balancing act: acids and alkalis working (or not!) together.
The term "alkaline" refers to substances that are basic—typically described in terms of pH, with alkaline solutions having a pH higher than 7 on the pH scale (in water). Essentially, an alkaline substance is a base, meaning it can neutralize acids. Think of it like this: acids often taste sour, while bases may taste bitter and can feel slippery or soapy. (Both strong acids and strong bases can be corrosive.)
You'll encounter "alkaline" most frequently in chemistry when discussing chemical reactions and solutions. For example, many cleaning products, like bleach and drain cleaner, are alkaline because they effectively dissolve grease and grime (breaking them down chemically).
But the concept extends beyond the lab. In agriculture, soil pH is crucial for plant growth; some plants thrive in alkaline soils while others prefer acidic ones. In consumer products, alkaline batteries use an alkaline electrolyte, and the label helps distinguish them from other battery types. You might also hear about alkaline water, which has a higher pH than regular drinking water and is marketed for potential health benefits (though evidence for broad health claims is debated). Similarly, an alkaline diet is a popular idea, but it’s worth remembering that the body regulates blood pH within a very narrow range.
So whether you're mixing chemicals, planning your meals, or tending to your garden, understanding "alkaline" helps describe substances that counteract acids and contribute to balance—in chemistry, biology, and beyond.
Examples
- 1
Batteries
This flashlight takes two AA alkaline batteries.
- 2
Soil conditions
Many plants will not grow well in strongly alkaline soil.
- 3
Skin sensitivity
That soap is too alkaline for sensitive skin.
Forms and spellings
1 form open this card.
Main spelling
- alkalineadjective